NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

1.    BUSINESS AND ORGANIZATION:

Quanta Services, Inc. (Quanta) is a leading provider of specialty contracting services, offering infrastructure solutions primarily to the electric power and natural gas and oil pipeline industries in North America and in select international markets. Quanta reports its results under three reportable segments: (1) Electric Power Infrastructure Services, (2) Natural Gas and Pipeline Infrastructure Services and (3) Fiber Optic Licensing and Other.

Electric Power Infrastructure Services Segment

The Electric Power Infrastructure Services segment provides comprehensive network solutions to customers in the electric power industry. Services performed by the Electric Power Infrastructure Services segment generally include the design, installation, upgrade, repair and maintenance of electric power transmission and distribution networks and substation facilities along with other engineering and technical services. This segment also provides emergency restoration services, including the repair of infrastructure damaged by inclement weather, the energized installation, maintenance and upgrade of electric power infrastructure utilizing unique bare hand and hot stick methods and Quanta’s proprietary robotic arm technologies, and the installation of “smart grid” technologies on electric power networks. In addition, this segment designs, installs and maintains renewable energy generation facilities, in particular solar and wind, and related switchyards and transmission networks. To a lesser extent, this segment provides services such as the design, installation, maintenance and repair of commercial and industrial wiring, installation of traffic networks and the installation of cable and control systems for light rail lines.

Natural Gas and Pipeline Infrastructure Services Segment

The Natural Gas and Pipeline Infrastructure Services segment provides comprehensive network solutions to customers involved in the transportation of natural gas, oil and other pipeline products. Services performed by the Natural Gas and Pipeline Infrastructure Services segment generally include the design, installation, repair and maintenance of pipeline transmission and distribution systems, gathering systems and compressor and pump stations, as well as related trenching, directional boring and automatic welding services. In addition, this segment’s services include pipeline protection, integrity testing, rehabilitation and replacement, and fabrication of pipeline support systems and related structures and facilities. To a lesser extent, this segment designs, installs and maintains airport fueling systems as well as water and sewer infrastructure.

Fiber Optic Licensing and Other Segment

The Fiber Optic Licensing and Other segment designs, procures, constructs, maintains and owns fiber optic telecommunications infrastructure in select markets and licenses the right to use these point-to-point fiber optic telecommunications facilities to its customers pursuant to licensing agreements, typically with terms from five to twenty-five years, inclusive of certain renewal options. Under these agreements, customers are provided the right to use a portion of the capacity of a fiber optic network, with the network owned and maintained by Quanta. The Fiber Optic Licensing and Other segment provides services to enterprise, education, carrier, financial services and healthcare customers, as well as other entities with high bandwidth telecommunication needs. The telecommunication services provided through this segment are subject to regulation by the Federal Communications Commission and certain state public utility commissions. The Fiber Optic Licensing and Other segment also provides various telecommunication infrastructure services on a limited basis primarily to Quanta’s customers in the electric power industry.

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Acquisitions

In the first quarter of 2012, Quanta acquired three businesses, which included an electric power infrastructure services company and a natural gas and pipeline infrastructure services company based in the United States and one electric power infrastructure services company based in Canada. These businesses have been reflected in Quanta’s condensed consolidated financial statements as of their respective acquisition dates. The aggregate consideration for these acquisitions consisted of approximately $37.2 million in cash, 1,264,687 shares of Quanta common stock valued at approximately $24.8 million and the repayment of $5.1 million in debt. These acquisitions allow Quanta to expand its capabilities and scope of services internationally and in the United States. The financial results of these businesses are generally included in the corresponding segment.

In the second quarter of 2012, Quanta acquired an electric power infrastructure services company with operations primarily in the Southeastern United States. This business has been reflected in Quanta’s condensed consolidated financial statements as of April 12, 2012. The aggregate consideration for this acquisition consisted of approximately $20.3 million in cash, 662,426 shares of Quanta common stock valued at approximately $12.5 million and the repayment of $5.9 million in debt. This acquisition allows Quanta to expand its capabilities and scope of services in the United States. The financial results of this business are generally included in Quanta’s Electric Power Infrastructure Services segment.

In the first quarter of 2013, Quanta acquired an electric power infrastructure services company. The results of operations related to this acquisition are not material and have been reflected in Quanta’s condensed consolidated financial statements beginning as of the date of the acquisition.

Dispositions

On December 3, 2012, Quanta sold substantially all of its domestic telecommunications infrastructure services operations and related subsidiaries to Dycom Industries, Inc. for net proceeds of approximately $265.0 million. Accordingly, Quanta has presented the results of operations, financial position and cash flows of such telecommunications subsidiaries as discontinued operations for the 2012 period presented in the accompanying consolidated financial statements.

Summarized financial information for discontinued operations is shown below (in thousands):

2.    SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES:

Principles of Consolidation

The consolidated financial statements of Quanta include the accounts of Quanta Services, Inc. and its wholly owned subsidiaries, which are also referred to as its operating units. The consolidated financial statements also include the accounts of certain of Quanta’s investments in joint ventures, which are either consolidated or proportionately consolidated, as discussed in the following summary of significant accounting policies. Investments in affiliated entities in which Quanta does not have a controlling financial interest, but over which Quanta has significant influence, usually because Quanta holds a voting interest of 20% to 50%, are accounted for using the equity method. All significant intercompany accounts and transactions have been eliminated in consolidation. Unless the context requires otherwise, references to Quanta include Quanta and its consolidated subsidiaries.

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Interim Condensed Consolidated Financial Information

These unaudited condensed consolidated financial statements have been prepared pursuant to the rules of the Securities and Exchange Commission (SEC). Certain information and footnote disclosures, normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States, have been condensed or omitted pursuant to those rules and regulations. Quanta believes that the disclosures made are adequate to make the information presented not misleading. In the opinion of management, all adjustments, consisting only of normal recurring adjustments, necessary to fairly state the financial position, results of operations, comprehensive income and cash flows with respect to the interim condensed consolidated financial statements have been included. The results of operations and comprehensive income for the interim periods are not necessarily indicative of the results for the entire fiscal year. The results of Quanta have historically been subject to significant seasonal fluctuations.

Quanta recommends that these unaudited condensed consolidated financial statements be read in conjunction with the audited consolidated financial statements and notes thereto of Quanta and its subsidiaries included in Quanta’s Annual Report on Form 10-K for the year ended December 31, 2012, which was filed with the SEC on March 1, 2013.

Use of Estimates and Assumptions

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires the use of estimates and assumptions by management in determining the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities known to exist as of the date the financial statements are published, and the reported amount of revenues and expenses recognized during the periods presented. Quanta reviews all significant estimates affecting its consolidated financial statements on a recurring basis and records the effect of any necessary adjustments prior to their publication. Judgments and estimates are based on Quanta’s beliefs and assumptions derived from information available at the time such judgments and estimates are made. Uncertainties with respect to such estimates and assumptions are inherent in the preparation of financial statements. Estimates are primarily used in Quanta’s assessment of the allowance for doubtful accounts, valuation of inventory, useful lives of assets, fair value assumptions in analyzing goodwill, other intangibles and long-lived asset impairments, equity investments, loan receivables, purchase price allocations, liabilities for self-insured and other claims, multi-employer pension plan withdrawal liabilities, revenue recognition for construction contracts and fiber optic licensing, share-based compensation, operating results of reportable segments, as well as the provision for income taxes and the calculation of uncertain tax positions.

Reclassifications

Certain reclassifications have been made in prior years’ condensed consolidated balance sheet and segment disclosures to conform to classifications used in the current year.

Cash and Cash Equivalents

Quanta had cash and cash equivalents of $366.6 million and $394.7 million as of March 31, 2013 and December 31, 2012. Cash consisting of interest-bearing demand deposits is carried at cost, which approximates fair value. Quanta considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents, which are carried at fair value. At March 31, 2013 and December 31, 2012, cash equivalents were $189.8 million and $92.5 million, which consisted primarily of money market mutual funds and investment grade commercial paper and are discussed further in “ Fair Value Measurements ” below. As of March 31, 2013 and December 31, 2012, cash and cash equivalents held in domestic bank accounts were approximately $254.7 million and $254.1 million, and cash and cash equivalents held in foreign bank accounts were approximately $111.9 million and $140.6 million.

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Current and Long-Term Accounts and Notes Receivable and Allowance for Doubtful Accounts

Quanta provides an allowance for doubtful accounts when collection of an account or note receivable is considered doubtful, and receivables are written off against the allowance when deemed uncollectible. Inherent in the assessment of the allowance for doubtful accounts are certain judgments and estimates including, among others, the customer’s access to capital, the customer’s willingness or ability to pay, general economic and market conditions and the ongoing relationship with the customer. Quanta considers accounts receivable delinquent after 30 days but does not generally include delinquent accounts in its analysis of the allowance for doubtful accounts unless the accounts receivable have been outstanding for at least 90 days. In addition to balances that have been outstanding for 90 days or more, Quanta also includes accounts receivable balances that relate to customers in bankruptcy or with other known difficulties in its analysis of the allowance for doubtful accounts. Material changes in Quanta’s customers’ business or cash flows, which may be impacted by negative economic and market conditions, could affect Quanta’s ability to collect amounts due from them. As of March 31, 2013 and December 31, 2012, Quanta had total allowances for doubtful accounts of approximately $5.4 million, all of which were included as a reduction of net current accounts receivable. Should customers experience financial difficulties or file for bankruptcy, or should anticipated recoveries relating to receivables in existing bankruptcies or other workout situations fail to materialize, Quanta could experience reduced cash flows and losses in excess of current allowances provided.

The balances billed but not paid by customers pursuant to retainage provisions in certain contracts are generally due upon completion of the contracts and acceptance by the customer. Based on Quanta’s experience with similar contracts in recent years, the majority of the retainage balances at each balance sheet date are expected to be collected within the next twelve months. Current retainage balances as of March 31, 2013 and December 31, 2012 were approximately $192.3 million and $180.6 million and are included in accounts receivable. Retainage balances with settlement dates beyond the next twelve months are included in other assets, net, and as of March 31, 2013 and December 31, 2012 were $29.3 million and $22.5 million.

Within accounts receivable, Quanta recognizes unbilled receivables in circumstances such as when revenues have been earned and recorded but the amount cannot be billed under the terms of the contract until a later date; costs have been incurred but are yet to be billed under cost-reimbursement type contracts; or amounts arise from routine lags in billing (for example, work completed one month but not billed until the next month). These balances do not include revenues accrued for work performed under fixed-price contracts as these amounts are recorded as costs and estimated earnings in excess of billings on uncompleted contracts. At March 31, 2013 and December 31, 2012, the balances of unbilled receivables included in accounts receivable were approximately $144.3 million and $127.5 million.

Goodwill and Other Intangibles

Quanta has recorded goodwill in connection with its acquisitions. Goodwill is subject to an annual assessment for impairment, which Quanta performs at the operating unit level. Each of Quanta’s operating units is organized into one of three internal divisions, which are closely aligned with Quanta’s reportable segments, based on the predominant type of work performed by the operating unit at the point in time the divisional designation is made. Because separate measures of assets and cash flows are not produced or utilized by management to evaluate segment performance, Quanta’s impairment assessments of its goodwill do not include any consideration of assets and cash flows by reportable segment. As a result, Quanta has determined that its individual operating units represent its reporting units for the purpose of assessing goodwill impairments.

Quanta has the option to first assess qualitative factors to determine whether it is necessary to perform the two-step fair value-based impairment test described below. If Quanta believes that, as a result of its qualitative assessment, it is more likely than not that the fair value of a reporting unit is less than its carrying amount, the quantitative impairment test is required. Otherwise, no further testing is required. Quanta can choose to perform the qualitative assessment on none, some or all of its reporting units. Quanta can also bypass the qualitative

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assessment for any reporting unit in any period and proceed directly to step one of the impairment test, and then resume performing the qualitative assessment in any subsequent period. Qualitative indicators including deterioration in macroeconomic conditions, declining financial performance, or a sustained decrease in share price, among other things, may trigger the need for annual or interim impairment testing of goodwill associated with one or all of the reporting units.

Quanta’s goodwill impairment assessment is performed at year-end, or more frequently if events or circumstances arise which indicate that goodwill may be impaired. For instance, a decrease in Quanta’s market capitalization below book value, a significant change in business climate or loss of a significant customer, as well as the qualitative indicators referenced above, may trigger the need for interim impairment testing of goodwill for one or all of its reporting units. The first step of the two-step fair value-based test involves comparing the fair value of each of Quanta’s reporting units with its carrying value, including goodwill. If the carrying value of the reporting unit exceeds its fair value, the second step is performed. The second step compares the carrying amount of the reporting unit’s goodwill to the implied fair value of its goodwill. If the implied fair value of goodwill is less than the carrying amount, an impairment loss would be recorded as a reduction to goodwill with a corresponding charge to operating expense.

Quanta determines the fair value of its reporting units using a weighted combination of the discounted cash flow, market multiple and market capitalization valuation approaches, with heavier weighting on the discounted cash flow method, as in management’s opinion, this method currently results in the most accurate calculation of a reporting unit’s fair value. Determining the fair value of a reporting unit requires judgment and the use of significant estimates and assumptions. Such estimates and assumptions include revenue growth rates, operating margins, discount rates, weighted average costs of capital and future market conditions, among others. Quanta believes the estimates and assumptions used in its impairment assessments are reasonable and based on available market information, but variations in any of the assumptions could result in materially different calculations of fair value and determinations of whether or not an impairment is indicated.

Under the discounted cash flow method, Quanta determines fair value based on the estimated future cash flows of each reporting unit, discounted to present value using risk-adjusted industry discount rates, which reflect the overall level of inherent risk of a reporting unit and the rate of return an outside investor would expect to earn. Cash flow projections are derived from budgeted amounts and operating forecasts (typically a two-year model) plus an estimate of later period cash flows, all of which are evaluated by management. Subsequent period cash flows are developed for each reporting unit using growth rates that management believes are reasonably likely to occur, along with a terminal value derived from the reporting unit’s earnings before interest, taxes, depreciation and amortization (EBITDA). The EBITDA multiples for each reporting unit are based on trailing twelve-month comparable industry data.

Under the market multiple and market capitalization approaches, Quanta determines the estimated fair value of each of its reporting units by applying transaction multiples to each reporting unit’s projected EBITDA and then averaging that estimate with similar historical calculations using either a one, two or three year average. For the market capitalization approach, Quanta adds a reasonable control premium, which is estimated as the premium that would be received in a sale of the reporting unit in an orderly transaction between market participants.

For recently acquired reporting units, a step one impairment test may indicate an implied fair value that is substantially similar to the reporting unit’s carrying value. Such similarities in value are generally an indication that management’s estimates of future cash flows associated with the recently acquired reporting unit remain relatively consistent with the assumptions that were used to derive its initial fair value. During the fourth quarter of 2012, a goodwill impairment analysis was performed for each of Quanta’s reporting units, which indicated that the implied fair value of each of Quanta’s reporting units, other than recently acquired reporting units, was substantially in excess of its carrying value. Following the analysis, management concluded that no impairment was indicated at any reporting unit. As discussed generally above, when evaluating the 2012 step one impairment test results, management considered many factors in determining whether or not an impairment of goodwill for any reporting

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unit was reasonably likely to occur in future periods, including future market conditions and the economic environment in which Quanta’s reporting units were operating. Additionally, management considered the sensitivity of its fair value estimates to changes in certain valuation assumptions and, after giving consideration to at least a 10% decrease in the fair value of each of Quanta’s reporting units, the results of the assessment at December 31, 2012 did not change. However, circumstances such as market declines, unfavorable economic conditions, the loss of a major customer or other factors could impact the valuation of goodwill in future periods.

Quanta’s intangible assets include customer relationships, backlog, trade names, non-compete agreements, patented rights and developed technology, all subject to amortization, along with other intangible assets not subject to amortization. The value of customer relationships is estimated as of the date a business is acquired based on the value-in-use concept utilizing the income approach, specifically the excess earnings method. The excess earnings analysis consists of discounting to present value the projected cash flows attributable to the customer relationships, with consideration given to customer contract renewals, the importance or lack thereof of existing customer relationships to Quanta’s business plan, income taxes and required rates of return. Quanta values backlog for acquired businesses as of the acquisition date based upon the contractual nature of the backlog within each service line, using the income approach to discount back to present value the cash flows attributable to the backlog. The value of trade names is estimated using the relief-from-royalty method of the income approach. This approach is based on the assumption that in lieu of ownership, a company would be willing to pay a royalty in order to exploit the related benefits of this intangible asset.

Quanta amortizes intangible assets based upon the estimated consumption of the economic benefits of each intangible asset, or on a straight-line basis if the pattern of economic benefits consumption cannot otherwise be reliably estimated. Intangible assets subject to amortization are reviewed for impairment and are tested for recoverability whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. For instance, a significant change in business climate or a loss of a significant customer, among other things, may trigger the need for interim impairment testing of intangible assets. An impairment loss would be recognized if the carrying amount of an intangible asset is not recoverable and its carrying amount exceeds its fair value.

Investments in Affiliates and Other Entities

In the normal course of business, Quanta enters into various types of investment arrangements, each having unique terms and conditions. These investments may include equity interests held by Quanta in business entities, including general or limited partnerships, contractual joint ventures, or other forms of equity participation. These investments may also include Quanta’s participation in different finance structures such as the extension of loans to project specific entities, the acquisition of convertible notes issued by project specific entities, or other strategic financing arrangements. Quanta determines whether such investments involve a variable interest entity (VIE) based on the characteristics of the subject entity. If the entity is determined to be a VIE, then management determines if Quanta is the primary beneficiary of the entity and whether or not consolidation of the VIE is required. The primary beneficiary consolidating the VIE must normally have both (i) the power to direct the activities of a VIE that most significantly affect the VIE’s economic performance and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE, in either case that could potentially be significant to the VIE. When Quanta is deemed to be the primary beneficiary, the VIE is consolidated and the other party’s equity interest in the VIE is accounted for as a noncontrolling interest. In cases where Quanta determines that it has an undivided interest in the assets, liabilities, revenues and profits of an unincorporated VIE (e.g., a general partnership interest), such amounts are consolidated on a basis proportional to Quanta’s ownership interest in the unincorporated entity.

Investments in entities of which Quanta is not the primary beneficiary, but over which Quanta has the ability to exercise significant influence, are accounted for using the equity method of accounting. Quanta’s share of net income or losses from unconsolidated equity investments is included in equity in earnings of unconsolidated affiliates in the consolidated statements of operations when applicable. Equity investments are reviewed for

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impairment by assessing whether any decline in the fair value of the investment below the carrying value is other than temporary. In making this determination, factors such as the ability to recover the carrying amount of the investment and the inability of the investee to sustain an earnings capacity are evaluated in determining whether a loss in value should be recognized. Any impairment losses would be recognized in other expense. Equity method investments are carried at original cost and are included in other assets, net in the consolidated balance sheet and are adjusted for Quanta’s proportionate share of the investees’ income, losses and distributions.

Quanta holds an equity ownership interest of approximately 31% in Howard Midstream Energy Partners, LLC (HEP). HEP is engaged in the business of owning, operating and constructing midstream plant and pipeline assets in the natural gas and oil pipeline industry. Quanta accounts for this investment using the equity method of accounting. During the first quarter of 2013, we invested an additional $8.5 million, along with other HEP members, to provide capital for planned midstream expansion projects. The carrying value of Quanta’s investment in HEP was approximately $99.0 million and $90.5 million at March 31, 2013 and December 31, 2012.

Revenue Recognition

Infrastructure Services  — Through its Electric Power Infrastructure Services and Natural Gas and Pipeline Infrastructure Services segments, Quanta designs, installs and maintains networks for customers in the electric power and natural gas and oil pipeline industries. These services may be provided pursuant to master service agreements, repair and maintenance contracts and fixed price and non-fixed price installation contracts. Pricing under these contracts may be competitive unit price, cost-plus/hourly (or time and materials basis) or fixed price (or lump sum basis), and the final terms and prices of these contracts are frequently negotiated with the customer. Under unit-based contracts, the utilization of an output-based measurement is appropriate for revenue recognition. Under these contracts, Quanta recognizes revenue as units are completed based on pricing established between Quanta and the customer for each unit of delivery, which best reflects the pattern in which the obligation to the customer is fulfilled. Under cost-plus/hourly and time and materials type contracts, Quanta recognizes revenue on an input basis, as labor hours are incurred and services are performed.

Revenues from fixed price contracts are recognized using the percentage-of-completion method, measured by the percentage of costs incurred to date to total estimated costs for each contract. These contracts provide for a fixed amount of revenues for the entire project. Such contracts provide that the customer accept completion of progress to date and compensate Quanta for services rendered, which may be measured in terms of units installed, hours expended or some other measure of progress. Contract costs include all direct materials, labor and subcontract costs and those indirect costs related to contract performance, such as indirect labor, supplies, tools, repairs and depreciation costs. Much of the material associated with Quanta’s work is owner-furnished and is therefore not included in contract revenues and costs. The cost estimation process is based on professional knowledge and experience of Quanta’s engineers, project managers and financial professionals. Changes in job performance, job conditions and final contract settlements are factors that influence management’s assessment of total contract value and the total estimated costs to complete those contracts and therefore Quanta’s profit recognition. Changes in these factors may result in revisions to costs and income, and their effects are recognized in the period in which the revisions are determined. Provisions for losses on uncompleted contracts are made in the period in which such losses are determined to be probable and the amount can be reasonably estimated.

Quanta may incur costs subject to change orders, whether approved or unapproved by the customer, and/or claims related to certain contracts. Quanta determines the probability that such costs will be recovered based upon evidence such as past practices with the customer, specific discussions or preliminary negotiations with the customer or verbal approvals. Quanta treats items as a cost of contract performance in the period incurred if it is not probable that the costs will be recovered or will recognize revenue if it is probable that the contract price will be adjusted and can be reliably estimated. As of March 31, 2013 and December 31, 2012, Quanta had approximately $222.4 million and $205.0 million of change orders and/or claims that had been included as contract price adjustments on certain contracts which were in the process of being negotiated in the normal

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course of business. These contract price adjustments represent management’s best estimate of additional contract revenues which have been earned and which management believes are probable of collection. The amounts ultimately realized by Quanta upon final acceptance by its customers could be higher or lower than such estimated amounts.

The current asset “Costs and estimated earnings in excess of billings on uncompleted contracts” represents revenues recognized in excess of amounts billed for fixed price contracts. The current liability “Billings in excess of costs and estimated earnings on uncompleted contracts” represents billings in excess of revenues recognized for fixed price contracts.

Fiber Optic Licensing  — The fiber optic licensing business constructs and licenses the right to use fiber optic telecommunications facilities to its customers pursuant to licensing agreements, typically with terms from five to twenty-five years, inclusive of certain renewal options. Under those agreements, customers are provided the right to use a portion of the capacity of a fiber optic facility, with the facility owned and maintained by Quanta. Revenues, including any initial fees or advance billings, are recognized ratably over the expected length of the agreements, including probable renewal periods. As of March 31, 2013 and December 31, 2012, initial fees and advance billings on these licensing agreements not yet recorded in revenue were $46.3 million and $46.4 million and are recognized as deferred revenue, with $37.1 million and $37.7 million considered to be long-term and included in other non-current liabilities. Minimum future licensing revenues expected to be recognized by Quanta pursuant to these agreements at March 31, 2013 are as follows (in thousands):

Income Taxes

Quanta follows the liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recorded for future tax consequences of temporary differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that are expected to be in effect when the underlying assets or liabilities are recovered or settled.

Quanta regularly evaluates valuation allowances established for deferred tax assets for which future realization is uncertain. The estimation of required valuation allowances includes estimates of future taxable income. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Quanta considers projected future taxable income and tax planning strategies in making this assessment. If actual future taxable income differs from these estimates, Quanta may not realize deferred tax assets to the extent estimated.

Quanta records reserves for income taxes related to certain tax positions in those instances where Quanta considers it more likely than not that additional taxes may be due in excess of amounts reflected on income tax returns filed. When recording reserves for expected tax consequences of uncertain positions, Quanta assumes that taxing authorities have full knowledge of the position and all relevant facts. Quanta continually reviews exposure

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to additional tax obligations, and as further information is known or events occur, changes in tax reserves may be recorded. To the extent interest and penalties may be assessed by taxing authorities on any underpayment of income tax, such amounts have been accrued and are classified in the provision for income taxes.

As of March 31, 2013, the total amount of unrecognized tax benefits relating to uncertain tax positions was $53.5 million, an increase from December 31, 2012 of $2.3 million. This increase in unrecognized tax benefits primarily relates to tax positions expected to be taken for 2013. Certain subsidiaries are under examination by various state and Canadian tax authorities for multiple periods. Quanta believes that it is reasonably possible that within the next 12 months unrecognized tax benefits may decrease up to $11.5 million as a result of settlements of these audits or as a result of the expiration of certain statutes of limitations.

The income tax laws and regulations are voluminous and are often ambiguous. As such, Quanta is required to make many subjective assumptions and judgments regarding its tax positions that could materially affect amounts recognized in its future consolidated balance sheets, statements of operations and comprehensive income.

Earnings Per Share

Basic earnings per share is computed using the weighted average number of common shares outstanding during the period, and diluted earnings per share is computed using the weighted average number of common shares outstanding during the period adjusted for all potentially dilutive common stock equivalents, except in cases where the effect of the common stock equivalent would be antidilutive.

Collective Bargaining Agreements

Several of Quanta’s operating units are parties to various collective bargaining agreements with unions that represent certain of their employees. The collective bargaining agreements expire at various times and have typically been renegotiated and renewed on terms similar to those in the expiring agreements. The agreements require the operating units to pay specified wages, provide certain benefits to their union employees and contribute certain amounts to multi-employer pension plans and employee benefit trusts. Quanta’s multi-employer pension plan contribution rates generally are specified in the collective bargaining agreements (usually on an annual basis), and contributions are made to the plans on a “pay-as-you-go” basis based on its union employee payrolls, which cannot be determined for future periods because the location and number of union employees that Quanta employs at any given time and the plans in which they may participate vary depending on the projects Quanta has ongoing at any time and the need for union resources in connection with those projects.

Stock-Based Compensation

Quanta recognizes compensation expense for restricted stock and restricted stock units (RSUs) to be settled in stock based on the fair value of the awards granted, net of estimated forfeitures, at the date of grant. The fair value of restricted stock awards and RSUs to be settled in stock is determined based on the number of shares or RSUs granted and the closing price of Quanta’s common stock on the date of grant. An estimate of future forfeitures is required in determining the period expense. Quanta uses historical data to estimate the forfeiture rate; however, these estimates are subject to change and may impact the value that will ultimately be realized as compensation expense. The resulting compensation expense from discretionary awards is recognized on a straight-line basis over the requisite service period, which is generally the vesting period, while compensation expense from performance-based awards is recognized using the graded vesting method over the requisite service period. Restricted stock awards and RSUs to be settled in stock are subject to forfeiture, restrictions on transfer and certain other conditions until vesting. During the restriction period, holders of restricted stock are entitled to vote and receive dividends on such shares. The cash flows resulting from the tax deductions in excess of the compensation expense recognized for restricted stock, RSUs to be settled in stock and stock options (excess tax benefit) are classified as financing cash flows.

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Compensation expense associated with liability based awards such as RSUs that are expected to be settled in cash is recognized based on a remeasurement of the fair value of the award at the end of each reporting period. RSUs to be settled in cash granted by Quanta under the Plans are intended to provide plan participants with cash performance incentives that are substantially equivalent to the risks and rewards of equity ownership in Quanta. RSUs to be settled in cash vest over a designated period, typically three years, and are subject to forfeiture under certain conditions, primarily termination of service. Upon vesting of RSUs to be settled in cash, the holders receive for each vested RSU an amount in cash equal to the fair market value on the vesting date of one share of Quanta common stock, as specified in the applicable award agreement. Generally, RSUs granted to plan participants residing in the U.S. provide for settlement in shares of common stock, and RSUs granted to plan participants residing outside the U.S. provide for settlement in cash.

Functional Currency and Translation of Financial Statements

The U.S. dollar is the functional currency for the majority of Quanta’s operations, which are primarily located within the United States. The functional currency for Quanta’s foreign operations, which are primarily located in Canada, is typically the currency of the country in which the foreign operating unit is located. Generally, the currency in which the operating unit transacts a majority of its activities, including billings, financing, payroll and other expenditures, would be considered the functional currency. Under the relevant accounting guidance, the treatment of foreign currency translation gains or losses is dependent upon management’s determination of the functional currency of each operating unit, which involves consideration of all relevant economic facts and circumstances affecting the operating unit. In preparing the consolidated financial statements, Quanta translates the financial statements of its foreign operating units from their functional currency into U.S. dollars. Statements of operations, comprehensive income and cash flows are translated at average monthly rates, while balance sheets are translated at the month-end exchange rates. The translation of the balance sheets at the month-end exchange rates results in translation gains or losses. If transactions are denominated in the operating units’ functional currency, the translation gains and losses are included as a separate component of equity under the caption “Accumulated other comprehensive income (loss).” If transactions are not denominated in the operating units’ functional currency, the translation gains and losses are included within the statement of operations.

Comprehensive Income

Components of comprehensive income include all changes in equity during a period except those resulting from changes in Quanta’s capital related accounts. Quanta records other comprehensive income (loss), net of tax, for foreign currency translation adjustments related to its foreign operations and for other revenues, expenses, gains and losses that are included in comprehensive income, but excluded from net income.

Litigation Costs and Reserves

Quanta records reserves when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. Costs incurred for litigation are expensed as incurred. Further details are presented in Note 9.

Fair Value Measurements

The carrying values of cash equivalents, accounts receivable, accounts payable and accrued expenses approximate fair value due to the short-term nature of these instruments. For disclosure purposes, qualifying assets and liabilities are categorized into three broad levels based on the priority of the inputs used to determine their fair values. The fair value hierarchy gives the highest priority to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). All of Quanta’s cash equivalents are categorized as Level 1 assets at March 31, 2013 and December 31, 2012, as all values are based on unadjusted quoted prices for identical assets in an active market that Quanta has the ability to access.

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In connection with Quanta’s acquisitions, identifiable intangible assets acquired include goodwill, backlog, customer relationships, trade names, covenants not-to-compete, patented rights and developed technology. Quanta utilizes the fair value premise as the primary basis for its valuation procedures, which is a market-based approach to determine the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Quanta periodically engages the services of an independent valuation firm when a new business is acquired to assist management with this valuation process, including assistance with the selection of appropriate valuation methodologies and the development of market-based valuation assumptions. Based on these considerations, management utilizes various valuation methods, including an income approach, a market approach and a cost approach, to determine the fair value of intangible assets acquired based on the appropriateness of each method in relation to the type of asset being valued. The assumptions used in these valuation methods are analyzed and compared, where possible, to available market data, such as industry-based weighted average costs of capital and discount rates, trade name royalty rates, public company valuation multiples and recent market acquisition multiples. The level of inputs used for these fair value measurements is the lowest level (Level 3). Quanta believes that these valuation methods appropriately represent the methods that would be used by other market participants in determining fair value.

Quanta uses fair value measurements on a routine basis in its assessment of assets classified as goodwill, other intangible assets and long-lived assets held and used. In accordance with its annual impairment test during the quarter ended December 31, 2012, the carrying amounts of such assets, including goodwill, were compared to their fair values. The inputs used for fair value measurements for goodwill, other intangible assets and long-lived assets held and used are the lowest level (Level 3) inputs, and Quanta uses the assistance of third party specialists to develop valuation assumptions.

Quanta also uses fair value measurements in connection with the valuation of its investments in private company equity interests and financing instruments. These valuations require significant management judgment due to the absence of quoted market prices, the inherent lack of liquidity and the long-term nature of such assets. Typically, the initial costs of these investments are considered to represent fair market value, as such amounts are negotiated between willing market participants. On a quarterly basis, Quanta performs an evaluation of its investments to determine if an other-than-temporary decline in the value of each investment has occurred and whether the recorded amount of each investment will be realizable. If an other-than-temporary decline in the value of an investment occurs, a fair value analysis would be performed to determine the degree to which the investment was impaired and a corresponding charge to earnings would be recorded during the period. These types of fair market value assessments are similar to other nonrecurring fair value measures used by Quanta, which include the use of significant judgment and available relevant market data. Such market data may include observations of the valuation of comparable companies, risk adjusted discount rates and an evaluation of the expected performance of the underlying portfolio asset, including historical and projected levels of profitability or cash flows. In addition, a variety of additional factors will be reviewed by management, including, but not limited to, contemporaneous financing and sales transactions with third parties, changes in market outlook and the third-party financing environment.

3.    NEW ACCOUNTING PRONOUNCEMENTS:

Adoption of New Accounting Pronouncements

On January 1, 2013, Quanta adopted an update that gives entities an option to first assess qualitative factors to determine whether the existence of events and circumstances indicate that it is more likely than not that its indefinite-lived intangible assets are impaired. If, based on its qualitative assessment, an entity concludes that it is more likely than not that the fair value of its indefinite-lived intangible assets is less than their carrying amount, quantitative impairment testing is required. However, if an entity concludes otherwise, quantitative impairment testing is not required. The adoption of this standard did not have a material effect on Quanta’s consolidated financial statements.

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Accounting Standards Not Yet Adopted

There were no significant accounting pronouncements issued but not yet adopted as of March 31, 2013.

As described in Note 2, Quanta’s operating units are organized into one of Quanta’s three internal divisions and accordingly, Quanta’s goodwill associated with each of its operating units has been aggregated on a divisional basis and reported in the table above. These divisions are closely aligned with Quanta’s reportable segments based on the predominant type of work performed by the operating units within the divisions. From time to time, operating units may be reorganized among Quanta’s internal divisions, as Quanta periodically re-evaluates strategies to better align its operations as business environments evolve.

Activity in Quanta’s intangible assets consists of the following (in thousands):

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Amortization expense for intangible assets was $5.3 million and $9.2 million for the three months ended March 31, 2013 and 2012. The estimated future aggregate amortization expense of intangible assets as of March 31, 2013 is set forth below (in thousands):

5.    PER SHARE INFORMATION:

Basic earnings per share is computed using the weighted average number of common shares outstanding during the period, and diluted earnings per share is computed using the weighted average number of common shares outstanding during the period adjusted for all potentially dilutive common stock equivalents, except in cases where the effect of the common stock equivalent would be antidilutive. The amounts used to compute the basic and diluted earnings per share for the three months ended March 31, 2013 and 2012 are illustrated below (in thousands):

For purposes of calculating diluted earnings per share, there were no adjustments required to derive Quanta’s net income attributable to common stock. For the three months ended March 31, 2013 and 2012, a nominal number of stock options were excluded from the computation of diluted earnings per share because the exercise prices of the stock options were greater than the average market price of Quanta’s common stock. The outstanding exchangeable shares of a Canadian subsidiary of Quanta that were issued pursuant to the acquisition of Valard Construction LP and certain of its affiliated entities (Valard) on October 25, 2010, which are exchangeable on a one-for-one basis with shares of Quanta common stock, are included in weighted average shares outstanding for basic and diluted earnings per share for the three months ended March 31, 2013 and 2012.

6.    DEBT OBLIGATIONS:

Credit Facility

Quanta has a credit agreement with various lenders that provides for a $700.0 million senior secured revolving credit facility maturing on August 2, 2016. Up to $100.0 million of the facility is available for

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revolving loans and letters of credit in certain alternative currencies in addition to the U.S. dollar. Borrowings under the credit agreement are to be used to refinance existing indebtedness and for working capital, capital expenditures and other general corporate purposes.

As of March 31, 2013, Quanta had approximately $183.6 million of letters of credit issued and no outstanding borrowings under the credit facility. The remaining $516.4 million was available for borrowings or issuing new letters of credit.

Amounts borrowed under the credit agreement in U.S. dollars bear interest, at Quanta’s option, at a rate equal to either (a) the Eurocurrency Rate (as defined in the credit agreement) plus 1.25% to 2.50%, as determined based on Quanta’s Consolidated Leverage Ratio (as described below), plus, if applicable, any Mandatory Cost (as defined in the credit agreement) required to compensate lenders for the cost of compliance with certain European regulatory requirements, or (b) the Base Rate (as described below) plus 0.25% to 1.50%, as determined based on Quanta’s Consolidated Leverage Ratio. Amounts borrowed under the credit agreement in any currency other than U.S. dollars bear interest at a rate equal to the Eurocurrency Rate plus 1.25% to 2.50%, as determined based on Quanta’s Consolidated Leverage Ratio, plus, if applicable, any Mandatory Cost. Standby letters of credit issued under the credit agreement are subject to a letter of credit fee of 1.25% to 2.50%, based on Quanta’s Consolidated Leverage Ratio, and Performance Letters of Credit (as defined in the credit agreement) issued under the credit agreement in support of certain contractual obligations are subject to a letter of credit fee of 0.75% to 1.50%, based on Quanta’s Consolidated Leverage Ratio. Quanta is also subject to a commitment fee of 0.20% to 0.45%, based on Quanta’s Consolidated Leverage Ratio, on any unused availability under the credit agreement. The Consolidated Leverage Ratio is the ratio of Quanta’s total funded debt to Consolidated EBITDA (as defined in the credit agreement). For purposes of calculating both the Consolidated Leverage Ratio and the maximum senior debt to Consolidated EBITDA ratio discussed below, total funded debt and total senior debt are reduced by all unrestricted cash and Cash Equivalents (as defined in the credit agreement) held by Quanta in excess of $25.0 million. The Base Rate equals the highest of (i) the Federal Funds Rate (as defined in the credit agreement) plus 1/2 of 1%, (ii) Bank of America’s prime rate and (iii) the Eurocurrency Rate plus 1.00%.

Subject to certain exceptions, the credit agreement is secured by substantially all of the assets of Quanta and its wholly owned U.S. subsidiaries, and by a pledge of all of the capital stock of Quanta’s wholly owned U.S. subsidiaries and 65% of the capital stock of the direct foreign subsidiaries of Quanta or its wholly owned U.S. subsidiaries. Quanta’s wholly owned U.S. subsidiaries also guarantee the repayment of all amounts due under the credit agreement. Subject to certain conditions, at any time Quanta maintains a corporate credit rating that is BBB- (stable) or higher by Standard & Poor’s Rating Services and a corporate family rating that is Baa3 (stable) or higher by Moody’s Investors Services, all collateral will be automatically released from these liens.

The credit agreement contains certain covenants, including a maximum Consolidated Leverage Ratio and a minimum interest coverage ratio, in each case as specified in the credit agreement. The credit agreement also contains a maximum senior debt to Consolidated EBITDA ratio, as specified in the credit agreement, which will be in effect at any time that the collateral securing the credit agreement has been and remains released. The credit agreement limits certain acquisitions, mergers and consolidations, indebtedness, capital expenditures, asset sales and prepayments of indebtedness and, subject to certain exceptions, prohibits liens on assets. The credit agreement also includes limits on the payment of dividends and stock repurchase programs in any fiscal year except those payments or other distributions payable solely in capital stock. As of March 31, 2013, Quanta was in compliance with all of the covenants in the credit agreement.

The credit agreement provides for customary events of default and includes cross-default provisions with Quanta’s underwriting, continuing indemnity and security agreement with its sureties and all of Quanta’s other debt instruments exceeding $30.0 million in borrowings or availability. If an event of default (as defined in the credit agreement) occurs and is continuing, on the terms and subject to the conditions set forth in the credit agreement, amounts outstanding under the credit agreement may be accelerated and may become or be declared immediately due and payable.

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7.    EQUITY:

Exchangeable Shares and Series F Preferred Stock

In connection with the acquisition of Valard on October 25, 2010, certain former owners of Valard received exchangeable shares of a Canadian subsidiary of Quanta which may be exchanged at the option of the holder for Quanta common stock on a one-for-one basis. The holders of exchangeable shares can make an exchange only once in any calendar quarter and must exchange a minimum of either 50,000 shares or, if less, the total number of remaining exchangeable shares registered in the name of the holder making the request. Quanta also issued one share of Quanta Series F preferred stock to a voting trust on behalf of the holders of the exchangeable shares. The Series F preferred stock provides the holders of the exchangeable shares voting rights in Quanta common stock equivalent to the number of exchangeable shares outstanding at any time. The combination of the exchangeable shares and the share of Series F preferred stock gives the holders of the exchangeable shares rights equivalent to Quanta common stockholders with respect to dividends, voting and other economic rights. During the quarter ended March 31, 2013, 409,110 exchangeable shares were exchanged for Quanta common stock.

Treasury Stock

Under the stock incentive plans described in Note 8, the tax withholding obligations of employees upon vesting of restricted stock awards and RSUs to be settled in common stock are typically satisfied by Quanta making such tax payments and withholding a number of vested shares having a value on the date of vesting equal to the tax withholding obligation. As a result, Quanta withheld 296,874 and 283,366 shares of Quanta common stock during the three months ended March 31, 2013 and 2012, with a total market value of $9.7 million and $6.0 million, in each case for settlement of employee tax liabilities. These shares and the related cost to acquire them were accounted for as an adjustment to the balance of treasury stock.

Noncontrolling Interests

Quanta holds investments in several joint ventures that provide infrastructure services under specific customer contracts. Each joint venture is owned equally by its members. Quanta has determined that certain of these joint ventures are variable interest entities, with Quanta providing the majority of the infrastructure services to the joint venture, which management believes most significantly influences the economic performance of the joint venture. Management has concluded that Quanta is the primary beneficiary of each of these joint ventures and has accounted for each on a consolidated basis. The other parties’ equity interests in these joint ventures have been accounted for as a noncontrolling interest in the condensed consolidated financial statements. Income attributable to the other joint venture members has been accounted for as a reduction of reported net income attributable to common stock in the amount of $4.8 million and $4.3 million for the three months ended March 31, 2013 and 2012. Equity in the consolidated assets and liabilities of these joint ventures that is attributable to the other joint venture members has been accounted for as a component of noncontrolling interests within total equity in the accompanying balance sheets.

The carrying value of the investments held by Quanta in all of its variable interest entities was approximately $4.7 million and $5.4 million at March 31, 2013 and December 31, 2012. The carrying value of investments held by the noncontrolling interests in these variable interest entities at March 31, 2013 and December 31, 2012 was $4.7 million and $5.4 million. During the three months ended March 31, 2013 and 2012, distributions to noncontrolling interests were $5.5 million and $2.5 million. There were no other changes in equity as a result of transfers to/from the noncontrolling interests during the three months ended March 31, 2013 or 2012. See Note 9 for further disclosures related to Quanta’s joint venture arrangements.

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8.    EQUITY-BASED COMPENSATION:

Stock Incentive Plans

On May 19, 2011, Quanta’s stockholders approved the Quanta Services, Inc. 2011 Omnibus Equity Incentive Plan (the 2011 Plan). The 2011 Plan provides for the award of non-qualified stock options, incentive (qualified) stock options (ISOs), stock appreciation rights, restricted stock, RSUs, stock bonus awards, performance compensation awards (including cash bonus awards) or any combination of the foregoing. The purpose of the 2011 Plan is to provide participants with additional performance incentives by increasing their proprietary interest in Quanta. Employees, directors, officers, consultants or advisors of Quanta or its affiliates are eligible to participate in the 2011 Plan, as are prospective employees, directors, officers, consultants or advisors of Quanta who have agreed to serve Quanta in those capacities. An aggregate of 11,750,000 shares of Quanta common stock may be issued pursuant to awards granted under the 2011 Plan.

Additionally, pursuant to the Quanta Services, Inc. 2007 Stock Incentive Plan (the 2007 Plan), which was adopted on May 24, 2007, Quanta may award restricted stock, incentive stock options and non-qualified stock options to eligible employees, directors, and certain consultants and advisors. An aggregate of 4,000,000 shares of common stock may be issued pursuant to awards granted under the 2007 Plan. Quanta also has a Restricted Stock Unit Plan (the RSU Plan), pursuant to which RSUs may be awarded to certain employees and consultants of Quanta’s Canadian operations.

Equity awards also remain outstanding under a prior plan adopted by Quanta, as well as under plans assumed by Quanta in connection with its acquisition of InfraSource Services, Inc. in 2007. While no further awards may be made under these plans, the awards outstanding under the plans continue to be governed by their terms. These plans, together with the 2011 Plan, the 2007 Plan and the RSU Plan, are referred to as the Plans.

Restricted Stock and Restricted Stock Units To Be Settled in Common Stock

During the three months ended March 31, 2013 and 2012, Quanta granted 1.3 million and 1.1 million shares of restricted stock and RSUs to be settled in common stock under the Plans with a weighted average grant date fair value of $29.47 and $21.65. The grant date fair value for awards of restricted stock and RSUs to be settled in common stock is based on the market value of Quanta common stock on the date of grant. Restricted stock and RSU awards to be settled in common stock are subject to forfeiture, restrictions on transfer and certain other conditions until vesting, which generally occurs over three years in equal annual installments. During the restriction period, holders are entitled to vote and receive dividends on such shares.

During the three months ended March 31, 2013 and 2012, 0.9 million and 0.8 million shares of restricted stock vested, with an approximate fair value at the time of vesting of $24.3 million and $16.6 million.

As of March 31, 2013, there was approximately $45.2 million of total unrecognized compensation cost related to unvested restricted stock and RSUs to be settled in common stock granted to both employees and non-employees. This cost is expected to be recognized over a weighted average period of 2.30 years.

Restricted Stock Units To Be Settled in Cash

Certain RSUs granted by Quanta under the Plans are intended to provide plan participants with cash performance incentives that are substantially equivalent to the risks and rewards of equity ownership in Quanta. These RSUs to be settled in cash vest over a designated period, typically three years, and are subject to forfeiture under certain conditions, primarily termination of service. Upon vesting of these RSUs, the holders receive for each vested RSU an amount in cash equal to the fair market value on the vesting date of one share of Quanta common stock, as specified in the applicable award agreement. Generally, RSUs granted to plan participants residing in the U.S. provide for settlement in shares of common stock, and RSUs granted to plan participants residing outside the U.S. provide for settlement in cash.

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Compensation expense related to RSUs to be settled in cash was $0.6 million and $0.4 million for the three months ended March 31, 2013 and 2012. Such expense is recorded in selling, general and administrative expenses. RSUs that may be settled only in cash are not included in the calculation of earnings per share, and the estimated earned value of such RSUs is classified as a liability. Quanta paid $0.5 million and $0.3 million to settle liabilities related to RSUs in the three months ended March 31, 2013 and 2012. Liabilities recorded for the estimated earned value of the RSUs outstanding to be settled in cash were $0.9 million and $0.8 million at March 31, 2013 and December 31, 2012.

9.    COMMITMENTS AND CONTINGENCIES:

Investments in Affiliates and Other Entities

As described in Note 7, Quanta holds investments in certain joint ventures with third parties for the purpose of providing infrastructure services under certain customer contracts. Losses incurred by these joint ventures are shared equally by the joint venture members. However, each member of the joint venture is jointly and severally liable for all of the obligations of the joint venture under the contract with the customer and therefore can be liable for full performance of the contract with the customer. In circumstances where Quanta’s participation in a joint venture qualifies as a general partnership, the joint venture partners are jointly and severally liable for all of the obligations of the joint venture including obligations owed to the customer or any other person or entity. Quanta is not aware of circumstances that would lead to future claims against it for material amounts in connection with these joint and several liabilities.

In the joint venture arrangements entered into by Quanta, each joint venturer indemnifies the other party for any liabilities incurred in excess of the liabilities such other party is obligated to bear under the respective joint venture agreement. It is possible, however, that Quanta could be required to pay or perform obligations in excess of its share if the other joint venturer failed or refused to pay or perform its share of the obligations. Quanta is not aware of circumstances that would lead to future claims against it for material amounts that would not be indemnified.

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Rent expense related to operating leases was approximately $24.3 million and $21.8 million for the three months ended March 31, 2013 and 2012.

Quanta has guaranteed the residual value on certain of its equipment operating leases. Quanta has agreed to pay any difference between this residual value and the fair market value of the underlying asset at the date of termination of the leases. At March 31, 2013, the maximum guaranteed residual value was approximately $239.0 million. Quanta believes that no significant payments will be made as a result of the difference between the fair market value of the leased equipment and the guaranteed residual value. However, there can be no assurance that significant payments will not be required in the future.

Committed Capital Expenditures

Quanta has committed capital for the expansion of its fiber optic network, although Quanta typically does not commit capital to new network expansions until it has a committed licensing arrangement in place with at least one customer. The amounts of committed capital expenditures are estimates of costs required to build the networks under contract. The actual capital expenditures related to building the networks could vary materially from these estimates. As of March 31, 2013, Quanta estimates these committed capital expenditures to be approximately $32.9 million for the period April 1, 2013 through December 31, 2013, $2.9 million for 2014 and $0.4 million for 2015. Quanta also committed capital for the expansion of its vehicle fleet in order to accommodate manufacturer lead times on certain types of vehicles. As of March 31, 2013, production orders for approximately $20.5 million had been issued with delivery dates expected to occur throughout 2013. Although Quanta has committed to purchase these vehicles at the time of their delivery, Quanta intends that these orders will be assigned to third party leasing companies and made available to Quanta under certain of its master equipment lease agreements, which will release Quanta from its capital commitment.

Litigation and Claims

Quanta is from time to time party to various lawsuits, claims and other legal proceedings that arise in the ordinary course of business. These actions typically seek, among other things, compensation for alleged personal injury, breach of contract and/or property damages, employment-related damages, punitive damages, civil penalties or other losses, or injunctive or declaratory relief. With respect to all such lawsuits, claims and proceedings, Quanta records a reserve when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. In addition, Quanta discloses matters for which management believes a material loss is at least reasonably possible. Except as otherwise stated below, none of these proceedings, separately or in the aggregate, are expected to have a material adverse effect on Quanta’s consolidated financial position, results of operations or cash flows. In all instances, management has assessed the matter based on current information and made a judgment concerning its potential outcome, giving due consideration to the nature of the claim, the amount and nature of damages sought and the probability of success. Management’s judgment may prove materially inaccurate, and such judgment is made subject to the known uncertainties of litigation.

California Fire Claim — Amador County.  In October 2004, a wildfire in Amador County, California, burned 16,800 acres. The United States Forest Service alleged that the fire originated as a result of the activities of a Quanta subsidiary crew performing vegetation management under a contract with Pacific Gas & Electric Co. (PG&E). In November 2007, the United States Department of Agriculture (USDA) sent a written demand to the Quanta subsidiary for payment of fire suppression costs of approximately $8.5 million. Quanta recorded a liability and corresponding insurance recovery receivable of approximately $8.5 million associated with this matter based on the written demand received from the USDA.

The USDA informally communicated that it also intends to seek past and future restoration and other damages of approximately $51.3 million, as well as other unspecified damages. PG&E tendered defense and indemnification for the matter to Quanta in 2010. On August 3, 2012, the USDA filed suit in the United States

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District Court, Eastern District of California, against Quanta, its subsidiary and PG&E, seeking unspecified damages for fire suppression costs, rehabilitation and restoration expenses, and loss of timber, habitat and environmental values, among other things, including recovery of fees and expenses.

Quanta notified its insurers, and two insurers participated under a reservation of rights. Two other insurers also participated but did not state a position regarding coverage. In January 2013, Quanta and its subsidiary filed a lawsuit in Amador County seeking a declaration that the insurers have a duty at their respective levels to pay any damages resulting from the USDA claims. The parties attended mediation in January 2013. While a resolution was not reached at the mediation, the parties continued negotiating through the mediator. As a result of those continued negotiations, a settlement-in-principle was reached with the USDA, subject to approval by the United States Department of Justice, for an amount within Quanta’s available insurance coverages. However, should the terms of the settlement-in-principle fail to be agreed in writing by the parties and approved by the Department of Justice, these claims could result in a significant uninsured loss and a material adverse effect on Quanta’s consolidated financial condition, results of operations and cash flows.

National Gas Company of Trinidad and Tobago Arbitration. On October 1, 2010, Mears Group, Inc. (Mears), a wholly owned subsidiary of Quanta, filed a request for arbitration with the International Chamber of Commerce (ICC) in London against the National Gas Company of Trinidad and Tobago (NGC). The request for arbitration arises out of a contract between Mears and NGC for horizontal directional drilling (HDD) services in connection with a shore approach of a natural gas pipeline. During pullback of the pipeline, a component on the drill rig operated by Mears failed, and the pipeline was lodged downhole. Subsequent efforts to salvage the pipeline by NGC, Mears, and other parties failed to dislodge the pipeline. NGC subsequently hired a separate HDD contractor to complete reworks.

Mears alleges breach of contract, among other things, and seeks recovery for works performed, standby costs, demobilization costs, and other expenses, totaling approximately $16.5 million, including taxes, and additionally seeks recovery of pre-judgment interest and attorneys’ fees and expenses. Mears contends in the arbitration that NGC breached the contract between the parties by providing a pipeline with insufficient buoyancy, weighing significantly more than the weight specified in the contract. In addition, Mears argues that NGC failed to provide a contractually required builders all-risk insurance policy naming Mears as an additional insured, which would have covered losses associated with a pullback failure. Moreover, Mears asserts that NGC agreed to indemnify Mears for losses to NGC’s equipment for events occurring during the project, and that any recovery by NGC is therefore barred.

NGC counterclaimed in the arbitration, asserting that Mears breached the contract and performed negligently by failing to provide a drilling component capable of withstanding loads during pullback and providing a hole of insufficient cleanliness such that debris and other materials contributed to excess forces experienced during Mears’ pullback of the pipeline. NGC seeks recovery for the costs of the salvage operations, the cost of the reworks, as well as other costs, totaling approximately $79.5 million, and additionally seeks recovery of pre-judgment interest and attorneys’ fees and expenses.

The arbitration hearings were completed during the third quarter of 2012, but no decision has been rendered. Mears also notified its insurers of the counterclaims, and although coverage was denied, Mears is continuing to pursue its insurers for coverage. Due to the nature of these claims, however, an adverse result in these proceedings could result in a significant uninsured loss that could have a material adverse effect on Quanta’s consolidated financial condition, results of operations and cash flows.

Concentrations of Credit Risk

Quanta is subject to concentrations of credit risk related primarily to its cash and cash equivalents and accounts receivable, including amounts related to unbilled accounts receivable and costs and estimated earnings in excess of billings on uncompleted contracts. Substantially all of Quanta’s cash investments are managed by

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what it believes to be high credit quality financial institutions. In accordance with Quanta’s investment policies, these institutions are authorized to invest this cash in a diversified portfolio of what Quanta believes to be high quality investments, which consist primarily of interest-bearing demand deposits, money market mutual funds and investment grade commercial paper with original maturities of three months or less. Although Quanta does not currently believe the principal amount of these investments is subject to any material risk of loss, changes in economic conditions could impact the interest income Quanta receives from these investments. In addition, Quanta grants credit under normal payment terms, generally without collateral, to its customers, which include electric power, natural gas and oil pipeline companies, governmental entities, general contractors, and builders, owners and managers of commercial and industrial properties located primarily in the United States and Canada. Consequently, Quanta is subject to potential credit risk related to changes in business and economic factors throughout the United States and Canada, which may be heightened as a result of uncertain economic and financial market conditions that have existed in recent years. However, Quanta generally has certain statutory lien rights with respect to services provided. Historically, some of Quanta’s customers have experienced significant financial difficulties, and others may experience financial difficulties in the future. These difficulties expose Quanta to increased risk related to collectability of billed and unbilled receivables and costs and estimated earnings in excess of billings on uncompleted contracts for services Quanta has performed. As of March 31 2013, two customers accounted for approximately 19% and 11% of consolidated billed and accrued accounts receivable. As of December 31, 2012, two customers accounted for approximately 16% and 11% of consolidated billed and accrued accounts receivable. Substantially all of the balance for the customer with 11% of consolidated billed and accrued accounts receivable as of March 31, 2013 and December 31, 2012 relates to one contract and is comprised primarily of certain contract change orders for which the customer acceptance process is ongoing. The services provided to these customers with billed and accrued accounts receivable balances greater than 10% of the consolidated balance relate primarily to Quanta’s Electric Power Infrastructure Services segment. For the three months ended March 31, 2013, one customer accounted for approximately 14% of consolidated revenues. The services provided to this customer relate primarily to Quanta’s Electric Power Infrastructure Services segment. No other customers represented 10% or more of revenues for the three months ended March 31, 2013 and 2012 or of billed and accrued accounts receivable as of March 31, 2013 and December 31, 2012.

Self-Insurance

Quanta is insured for employer’s liability, general liability, auto liability and workers’ compensation claims. Since August 1, 2009, all policy deductible levels are $5.0 million per occurrence, other than employer’s liability, which is subject to a deductible of $1.0 million. Quanta also has employee health care benefit plans for most employees not subject to collective bargaining agreements, of which the primary plan is subject to a deductible of $375,000 per claimant per year.

Losses under all of these insurance programs are accrued based upon Quanta’s estimates of the ultimate liability for claims reported and an estimate of claims incurred but not reported, with assistance from third-party actuaries. These insurance liabilities are difficult to assess and estimate due to unknown factors, including the severity of an injury, the extent of damage, the determination of Quanta’s liability in proportion to other parties and the number of incidents not reported. The accruals are based upon known facts and historical trends, and management believes such accruals are adequate. As of March 31, 2013 and December 31, 2012, the gross amount accrued for insurance claims totaled $167.9 million and $160.8 million, with $125.7 million and $120.2 million considered to be long-term and included in other non-current liabilities. Related insurance recoveries/receivables as of March 31, 2013 and December 31, 2012 were $22.4 million and $22.2 million, of which $2.2 million and $2.3 million are included in prepaid expenses and other current assets and $20.2 million and $19.9 million are included in other assets, net.

Quanta renews its insurance policies on an annual basis, and therefore deductibles and levels of insurance coverage may change in future periods. In addition, insurers may cancel Quanta’s coverage or determine to exclude certain items from coverage, or Quanta may elect not to obtain certain types or incremental levels of

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insurance if it believes that the cost to obtain such coverage exceeds the additional benefits obtained. In any such event, Quanta’s overall risk exposure would increase, which could negatively affect its results of operations, financial condition and cash flows.

Letters of Credit

Certain of Quanta’s vendors require letters of credit to ensure reimbursement for amounts they are disbursing on its behalf, such as to beneficiaries under its self-funded insurance programs. In addition, from time to time, certain customers require Quanta to post letters of credit to ensure payment to its subcontractors and vendors and to guarantee performance under its contracts. Such letters of credit are generally issued by a bank or similar financial institution, typically pursuant to Quanta’s credit facility. Each letter of credit commits the issuer to pay specified amounts to the holder of the letter of credit if the holder demonstrates that Quanta has failed to perform specified actions. If this were to occur, Quanta would be required to reimburse the issuer of the letter of credit. Depending on the circumstances of such a reimbursement, Quanta may also be required to record a charge to earnings for the reimbursement. Quanta does not believe that it is likely that any material claims will be made under a letter of credit in the foreseeable future.

As of March 31, 2013, Quanta had $183.6 million in letters of credit outstanding under its credit facility primarily to secure obligations under its casualty insurance program. These are irrevocable stand-by letters of credit with maturities generally expiring at various times throughout 2013 and 2014. Upon maturity, it is expected that the majority of these letters of credit will be renewed for subsequent one-year periods.

Performance Bonds and Parent Guarantees

In certain circumstances, Quanta is required to provide performance bonds in connection with its contractual commitments. Quanta has indemnified its sureties for any expenses paid out under these performance bonds. As of March 31, 2013, the total amount of outstanding performance bonds was approximately $2.12 billion, and the estimated cost to complete these bonded projects was approximately $500.3 million.

Quanta, from time to time, guarantees the obligations of its wholly owned subsidiaries, including obligations under certain contracts with customers, certain lease obligations and, in some states, obligations in connection with obtaining contractors’ licenses. Quanta is not aware of any material obligations for performance or payment asserted against it under any of these guarantees.

Employment Agreements

Quanta has various employment agreements with certain executives and other employees, which provide for compensation and certain other benefits and for severance payments under certain circumstances. Certain employment agreements also contain clauses that become effective upon a change of control of Quanta. Quanta may be obligated to pay certain amounts to such employees upon the occurrence of any of the defined events in the various employment agreements.

Collective Bargaining Agreements

Several of Quanta’s operating units are parties to various collective bargaining agreements with unions that represent certain of their employees. The collective bargaining agreements expire at various times and have typically been renegotiated and renewed on terms similar to those in the expiring agreements. The agreements require the operating units to pay specified wages, provide certain benefits to their union employees and contribute certain amounts to multi-employer pension plans and employee benefit trusts. Quanta’s multiemployer pension plan contribution rates generally are specified in the collective bargaining agreements (usually on an annual basis), and contributions are made to the plans on a “pay-as-you-go” basis based on its union employee payrolls, which cannot be determined for future periods because the location and number of union employees that

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Quanta employs at any given time and the plans in which they may participate vary depending on the projects Quanta has ongoing at any time and the need for union resources in connection with those projects.

The Pension Protection Act of 2006 (PPA) also added special funding and operational rules generally applicable to plan years beginning after 2007 for multi-employer plans that are classified as “endangered,” “seriously endangered” or “critical” status based on multiple factors (including, for example, the plan’s funded percentage, cash flow position and whether it is projected to experience a minimum funding deficiency). Plans in these classifications must adopt measures to improve their funded status through a funding improvement or rehabilitation plan, as applicable, which may require additional contributions from employers (which may take the form of a surcharge on benefit contributions) and/or modifications to retiree benefits. Certain plans to which Quanta contributes or may contribute in the future are in “endangered,” “seriously endangered” or “critical” status. The amount of additional funds, if any, that Quanta may be obligated to contribute to these plans in the future cannot be estimated due to uncertainty of the future levels of work that require the specific use of union employees covered by these plans, as well as the future contribution levels and possible surcharges on contributions applicable to these plans.

Quanta may be subject to additional liabilities imposed by law as a result of its participation in multi-employer defined benefit pension plans. For example, the Employee Retirement Income Security Act of 1974, as amended by the Multi-Employer Pension Plan Amendments Act of 1980, imposes certain liabilities upon an employer who is a contributor to a multi-employer pension plan if the employer withdraws from the plan or the plan is terminated or experiences a mass withdrawal. These liabilities include an allocable share of the unfunded vested benefits in the plan for all plan participants, not merely the benefits payable to a contributing employer’s own retirees. As a result, participating employers may bear a higher proportion of liability for unfunded vested benefits if other participating employers cease to contribute or withdraw, with the reallocation of liability being more acute in cases when a withdrawn employer is insolvent or otherwise fails to pay its withdrawal liability. Other than as described below, Quanta is not aware of any material amounts of withdrawal liability that have been incurred as a result of a withdrawal by any of Quanta’s operating units from any multi-employer defined benefit pension plans.

In the fourth quarter of 2011, Quanta recorded a partial withdrawal liability of approximately $32.6 million related to the withdrawal by certain Quanta subsidiaries from the Central States, Southeast and Southwest Areas Pension Plan (the Central States Plan). The partial withdrawal liability recognized by Quanta was based on estimates received from the Central States Plan during 2011 for a complete withdrawal by all Quanta companies participating in the Central States Plan. The withdrawal followed an amendment to a collective bargaining agreement with the International Brotherhood of Teamsters that eliminated obligations to contribute to the Central States Plan, which is in critical status and is significantly underfunded as to its vested benefit obligations. The amendment was negotiated by the Pipe Line Contractors Association (PLCA) on behalf of its members, which include the Quanta subsidiaries that withdrew from the Central States Plan. Quanta believed that withdrawing from the Central States Plan in the fourth quarter of 2011 was advantageous because it limited Quanta’s exposure to increased liabilities from a future withdrawal if the underfunded status of the Central States Plan deteriorates further. Quanta and other PLCA members now contribute to a different multi-employer pension plan on behalf of Teamsters employees.

The Central States Plan has asserted that the withdrawal of the PLCA members was not effective in 2011, although Quanta believes that a legally effective withdrawal occurred in the fourth quarter of 2011. During the third quarter of 2012, the Central States Plan provided Quanta with an estimate of the potential withdrawal liability, indicating that the withdrawal liability is approximately $32.8 million based on a partial withdrawal in the fourth quarter of 2011, approximately $39.7 million based on a partial withdrawal in the first quarter of 2012, or approximately $40.1 million based on a complete withdrawal in 2012. Quanta continues to dispute the assertions of the Central States Plan regarding the effective date of the partial withdrawal. Once an assessment is received, Quanta may seek to challenge and further negotiate the amount of the assessment. As a result, the final

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partial withdrawal liability cannot yet be determined with certainty and could be materially higher or lower than the $32.6 million Quanta recognized in the fourth quarter of 2011.

Certain other Quanta subsidiaries continued to participate in the Central States Plan through the end of 2012. The consequences of withdrawal of these subsidiaries from the plan will depend on various factors, including negotiation of the terms of the collective bargaining agreements under which the subsidiaries participate and whether exemptions from withdrawal liability applicable to construction industry employers will be available. Given the unknown nature of some of these factors, the amount or timing of any liability upon withdrawal of the subsidiaries remaining in the Central States Plan is uncertain. However, Quanta currently does not expect the incremental liability upon withdrawal of the subsidiaries remaining in the Central States Plan to be material.

Indemnities

Quanta generally indemnifies its customers for the services it provides under its contracts, as well as other specified liabilities, which may subject Quanta to indemnity claims and liabilities and related litigation. Quanta has also indemnified various parties against specified liabilities that those parties might incur in the future in connection with Quanta’s previous acquisition or disposition of certain companies. The indemnities under acquisition or disposition agreements are usually contingent upon the other party incurring liabilities that reach specified thresholds. As of March 31, 2013, except as otherwise set forth above in Litigation and Claims , Quanta does not believe any material liabilities for asserted claims exist against it in connection with any of these indemnity obligations.

10.    SEGMENT INFORMATION:

Quanta presents its operations under three reportable segments: (1) Electric Power Infrastructure Services, (2) Natural Gas and Pipeline Infrastructure Services and (3) Fiber Optic Licensing and Other. This structure is generally based on the broad end-user markets for Quanta’s services. See Note 1 for additional information regarding Quanta’s reportable segments.

Quanta’s segment results are derived from the types of services provided across its operating units in each of the end user markets described above. Quanta’s entrepreneurial business model allows each of its operating units to serve the same or similar customers and to provide a range of services across end user markets. Quanta’s operating units are organized into one of three internal divisions, namely, the electric power division, natural gas and pipeline division and fiber optic licensing division. These internal divisions are closely aligned with the reportable segments described above based on their operating units’ predominant type of work.

Reportable segment information, including revenues and operating income by type of work, is gathered from each operating unit for the purpose of evaluating segment performance in support of Quanta’s market strategies. These classifications of Quanta’s operating unit revenues by type of work for segment reporting purposes can at times require judgment on the part of management. Quanta’s operating units may perform joint infrastructure service projects for customers in multiple industries, deliver multiple types of network services under a single customer contract or provide service across industries, for example, joint trenching projects to install distribution lines for electric power and natural gas customers.

In addition, Quanta’s integrated operations and common administrative support at each of its operating units require that certain allocations, including allocations of shared and indirect costs, such as facility costs, indirect operating expenses, including depreciation, and general and administrative costs, to determine operating segment profitability. Corporate costs, such as payroll and benefits, employee travel expenses, facility costs, professional fees, acquisition costs and amortization related to certain intangible assets are not allocated.

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Summarized financial information for Quanta’s reportable segments is presented in the following tables (in thousands):

Separate measures of Quanta’s assets and cash flows by reportable segment, including capital expenditures, are not produced or utilized by management to evaluate segment performance. Quanta’s fixed assets, including operating machinery, equipment and vehicles, as well as office equipment, buildings and leasehold improvements, which are held at the operating unit level, are used on an interchangeable basis across its reportable segments. As such, for reporting purposes, total depreciation expense is allocated each quarter among Quanta’s reportable segments based on the ratio of each reportable segment’s revenue contribution to consolidated revenues.

Foreign Operations

During the three months ended March 31, 2013 and 2012, Quanta derived $299.2 million and $249.8 million of its revenues from foreign operations. Of Quanta’s foreign revenues, approximately 96% was earned in Canada during each of the three months ended March 31, 2013 and 2012. In addition, Quanta held property and equipment of $156.5 million and $151.9 million in foreign countries, primarily Canada, as of March 31, 2013 and December 31, 2012.

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