INTRODUCTION

Ambac Financial Group, Inc. (“Ambac” or the “Company”), headquartered in New York City, is a financial services holding company incorporated in the State of Delaware on April 29, 1991. On May 1, 2013 (the “Effective Date”), Ambac emerged from Chapter 11 bankruptcy protection when the Second Modified Fifth Amended Plan of Reorganization of Ambac Financial Group, Inc. (the “Reorganization Plan”) became effective. On December 26, 2013, the United States Bankruptcy Court for the Southern District of New York (the “Bankruptcy Court”) entered an order of final decree closing Ambac’s Chapter 11 case. Ambac filed a voluntary petition for relief under Chapter 11 of the United States Bankruptcy Code in the Bankruptcy Court on November 8, 2010 as a result of losses incurred since the beginning of the financial crisis in 2007. Refer to Note 1 to the Consolidated Financial Statements in Part II, Item 8 of this Form 10-K for further discussion of Ambac’s bankruptcy.

Ambac has two reportable business segments: Financial Guarantee and Financial Services.

Ambac’s Financial Guarantee business segment is conducted through its primary operating subsidiary, Ambac Assurance Corporation (“Ambac Assurance”), and its wholly owned subsidiary, Ambac Assurance UK Limited. (“Ambac UK”). Insurance policies insured by Ambac Assurance and Ambac UK guarantee payment when due of the principal and interest on the obligation guaranteed. Ambac Assurance also has another wholly-owned financial guarantee subsidiary, Everspan Financial Guarantee Corp. (“Everspan”), which has been in runoff since its acquisition in 1997. The deterioration of Ambac Assurance’s financial condition resulting from losses in its insured portfolio since 2007 has prevented Ambac Assurance from being able to write new business. An inability to write new business has and will continue to negatively impact Ambac’s future operations and financial results. Ambac Assurance’s ability to pay dividends and, as a result, Ambac’s liquidity, have been significantly restricted by the deterioration of Ambac Assurance’s financial condition, by the rehabilitation of the Segregated Account (defined below) and by the terms of the Settlement Agreement, dated as of June 7, 2010, by and among Ambac Assurance, Ambac Credit Products LLC (“ACP”), Ambac and counterparties to credit default swaps with ACP that were guaranteed by Ambac Assurance. Ambac Assurance is also restricted in its ability to pay dividends pursuant to the terms of its Auction Market Preferred Shares. It is highly unlikely that Ambac Assurance will be able to make dividend payments to Ambac for the foreseeable future. Refer to Part I, Item 1, “Insurance Regulatory Matters – Dividend Restrictions, Including Contractual Restrictions” and Note 9 to the Consolidated Financial Statements located in Part II, Item 8, for more information on dividend payment restrictions.

In March 2010, Ambac Assurance established a segregated account pursuant to Wisconsin Stat. §611.24(2) (the “Segregated Account”) to segregate certain segments of Ambac Assurance’s liabilities. The Office of the Commissioner of Insurance for the State of Wisconsin (“OCI” (which term shall be understood to refer to such office as regulator of Ambac Assurance and to refer to the Commissioner of Insurance for the State of Wisconsin as rehabilitator of the Segregated Account (the “Rehabilitator”), as the context requires)) commenced rehabilitation proceedings in the Wisconsin Circuit Court for Dane County (the “Rehabilitation Court”) with respect to the Segregated Account (the “Segregated Account Rehabilitation Proceedings”) in order to permit the OCI to facilitate an orderly run-off and/or settlement of the liabilities allocated to the Segregated Account pursuant to the provisions of the Wisconsin Insurers Rehabilitation and Liquidation Act. Ambac Assurance is not, itself, in rehabilitation proceedings. Refer to Note 1 to the Consolidated Financial Statements located in Part II, Item 8, for more information on the Segregated Account.

Ambac’s Financial Services business segment is conducted through its financial services subsidiaries, which provide financial and investment products, including investment agreements, funding conduits and interest rate swaps, principally to the clients of its financial guarantee business. Ambac Assurance insured all of the

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obligations of its financial services subsidiaries. These businesses are in active runoff, which is being effectuated by means including transaction terminations, settlements, and scheduled amortization of contracts. The Financial Services business also maintains interest rate derivatives to mitigate exposure to floating rate insured obligations in the Financial Guarantee segment.

Following emergence from bankruptcy, Ambac’s primary goal is to maximize shareholder value through executing the following key strategies:

Opportunities for de-risking transactions depend on market conditions, including the perception of Ambac Assurance’s creditworthiness, the structure of the underlying risk and associated policy, as well as other factors. Ambac Assurance’s ability to further commute policies or purchase securities may be limited by available liquidity. The execution of Ambac’s strategy with respect to liabilities and associated rights allocated to the Segregated Account is subject to the authority of the Rehabilitator to control the management of the Segregated Account. In exercising such authority, the Rehabilitator will act for the benefit of policyholders, and will not take into account the interests of Ambac. Similarly, by operation of the contracts executed in connection with the establishment, and subsequent rehabilitation, of the Segregated Account, the Rehabilitator retains rights to oversee and approve certain actions taken in respect of Ambac Assurance. This oversight by the Rehabilitator could impair Ambac’s ability to execute certain of its strategies. Refer to Note 1 to the Consolidated Financial Statements located in Part II, Item 8, for more information on the contracts between Ambac Assurance and the Segregated Account.

Although we are exploring new business opportunities for Ambac, no assurance can be given that we will be able to identify or execute the acquisition or development of any new business. In addition there can be no assurance that we will be able to generate or obtain the financial and other resources that may be required to finance the acquisition or development of any new business. Due to these factors, as well as uncertainties relating to the ability of Ambac Assurance to deliver value to Ambac, the value of our securities is speculative. For additional risks and uncertainties concerning Ambac, please refer to Part I, Item 1A of this Form 10-K.

We followed the accounting prescribed by the Reorganizations Topic of the ASC from the period starting with Ambac’s bankruptcy filing through to our emergence from bankruptcy. Following the Company’s emergence from bankruptcy on May 1, 2013, the consolidated financial statements reflect the application of fresh start reporting (“Fresh Start”), incorporating, among other things, the discharge of debt obligations, issuance of new common stock, and fair value adjustments. The effects of the reorganization and Fresh Start adjustments are recorded in Predecessor Ambac’s Consolidated Statement of Total Comprehensive Income for the period ended April 30, 2013. The financial results of the Company for the periods from May 1, 2013 are referred to as “Successor” and the financial results for the periods through April 30, 2013 (“Fresh Start Reporting Date”) are referred to as “Predecessor.” The 2013 Successor Period and the 2013 Predecessor Period are distinct reporting periods. The effects of emergence and Fresh Start had a material impact on the comparability of our results of operations between these periods, as discussed below. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations” located in Part II, Item 7 of this Form 10-K for further information.

Our Internet address is www.ambac.com. We make available free of charge, through the investor relations section of our web site, annual reports on Form 10-K, quarterly reports on Form 10-Q and current reports on

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Form 8-K, and any amendments to those reports, filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended, as well as proxy statements, as soon as reasonably practicable after we electronically file such material with, or furnish it to, the U.S. Securities and Exchange Commission. Our Investor Relations Department can be contacted at Ambac Financial Group, Inc., One State Street Plaza, New York, New York 10004, Attn: Investor Relations, telephone: 212-208-3222. The reference to our website address does not constitute inclusion or incorporation by reference of the information contained on our website in this Form 10-K or other filings with the SEC, and the information contained on our website is not part of this document.

Financial information concerning our business segments for each of 2013 and 2012 is set forth in “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” “Quantitative and Qualitative Disclosures About Market Risk,” and the Consolidated Financial Statements and the Notes thereto, included elsewhere in this Form 10-K.

Financial Guarantee Segment

The Financial Guarantee segment includes insurance policies and credit derivative contracts. Generally, financial guarantees provide an unconditional and irrevocable guarantee which protects the holder of a debt obligation against non-payment when due. Pursuant to such guarantees, Ambac Assurance and its subsidiaries make payments if the obligor responsible for making payments fails to do so when scheduled. Credit derivatives permit certain counterparties to assert mark-to-market termination claims; however, the assertion of such mark-to-market claims has been enjoined by the Rehabilitation Court. See discussion of “Ambac Assurance Liquidity” in Part II, Item 7 included in this Form 10-K for further information.

Ambac’s financial guarantee insurance policies and credit derivative contracts expose the company to the direct credit risk of the assets and/or obligors supporting the guaranteed obligation. In addition to such direct credit exposure, Ambac’s insured transactions expose us to indirect risks that may increase our overall risk, such as credit risk separate from, but correlated with, our direct credit risk, market risk, model risk, economic risk, natural disaster risk and mortality or other non credit type risks.

Ambac Assurance derives financial guarantee revenues from: (i) premiums earned from insurance contracts; (ii) net investment income; (iii) revenue from credit derivative transactions; (iv) net realized gains and losses from sales of investment securities; and (v) amendment and consent fees. Financial guarantee expenditures include (i) loss and commutation payments for credit exposures that have experienced significant credit deterioration and/or default; (ii) loss-related expenses, including those relating to the remediation of problem credits, and (iii) operating expenses. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations” located in Part II, Item 7 of this Form 10-K for further information. Prior to the discontinuance of the issuance of new financial guarantees, premiums for financial guarantees were received either upfront (typical of public finance obligations) or on an installment basis from the cash flows generated by the underlying assets (typical of structured finance obligations). Despite not underwriting new business, Ambac continues to collect premiums on its existing portfolio of guarantees that pay premiums on an installment basis.

Risk Management

Ambac’s Asset Liability Management Committee (“ALCO”) is a multidisciplinary committee with the objective to implement and foster an enterprise wide culture and approach to liquidity management, asset valuation, hedging, and risk remediation. Members of ALCO include the Chief Executive Officer, Chief Financial Officer and senior managers from investment management, capital markets and risk management. ALCO has scheduled monthly meetings and will also meet on an ad hoc basis to consider, for example, the commutation of distressed financial guarantee exposures.

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The insured portfolio Risk Management group is primarily responsible for the development, implementation and oversight of loss mitigation strategies, surveillance and remediation of the financial guarantee portfolio (including through the pursuit of recoveries in respect of paid claims and commutations of policies). These activities are integral to Ambac’s strategy of mitigating losses on poorly performing transactions. As a consequence of the Segregated Account Rehabilitation Proceedings, the Rehabilitator retains operational control and decision-making authority with respect to all matters related to the Segregated Account, including surveillance, remediation and loss mitigation. The Rehabilitator operates the Segregated Account through a management services contract executed between Ambac Assurance and the Segregated Account pursuant to which the Risk Management group provides surveillance, remediation and loss mitigation services to the Segregated Account.

Furthermore, by virtue of the contracts executed between Ambac Assurance and the Segregated Account, the Rehabilitator retains the discretion to oversee and approve certain actions taken by Ambac Assurance in respect of assets and liabilities that have not been allocated to the Segregated Account. Refer to Note 1 to the Consolidated Financial Statements located in Part II, Item 8, for more information on the contracts between Ambac Assurance and the Segregated Account. As such, the following discussion of Ambac’s risk management practices is qualified by reference to the Rehabilitator’s exercise of its discretion to alter or eliminate any of these risk management practices.

Ambac’s risk management function for the insured portfolio has an organizational structure designed around the two major areas of focus: Portfolio Risk Management and Analysis (“PRM”) and Credit Risk Management (“CRM”). As a result of the current credit and economic environment, Ambac heightened its surveillance efforts on all exposures, focusing on the identification of credits and asset types across the portfolio that were likely to experience increased stress or potential for losses. The senior managers within the risk management groups report directly to the Chief Executive Officer and regularly inform and update the Audit Committee of the Board of Directors of Ambac and Ambac Assurance with respect to risk-related topics in the insured portfolio.

Portfolio Risk Management and Analysis

This group’s focus is on remediation, loss mitigation, risk reduction and surveillance. Risk Management personnel perform periodic surveillance reviews of exposures according to a schedule based on the risk profile of the guaranteed obligations or as necessitated by specific credit events or other macro-economic variables. The monitoring activities are designed to detect deterioration in credit quality or changes in the economic, regulatory or political environment which could adversely impact the portfolio. Active surveillance enables PRM to track single credit migration and industry credit trends. In some cases, PRM will engage workout experts or attorneys and other consultants with appropriate expertise in the targeted loss mitigation area to assist management in examining the underlying contracts or collateral, providing industry specific advice and/or executing strategies.

Analysts review, on a regular and ad hoc basis, credits in the book of business. Risk-adjusted surveillance strategies have been developed for each bond type with review periods and scope of review based upon each bond type’s risk profile. The risk profile is assessed regularly in response to our own experience and judgments or external factors such as the economic environment and industry trends. The focus of the surveillance review is to assess performance, identify credit trends and recommend appropriate credit classifications, ratings and changes to a transaction or bond type’s review period. If a problem is detected, the group focuses on loss mitigation by recommending appropriate action and working with the issuer, trustee, bond counsel, servicer and other interested parties in an attempt to remediate the problem and minimize Ambac Assurance’s exposure to potential loss. Those credits that are either in default or have developed problems that eventually may lead to a default or claim payment are tracked closely by the appropriate surveillance team, senior risk managers and discussed at regularly scheduled meetings with CRM (see discussion following in “Credit Risk Management”).

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In structured transactions, including structured public finance transactions, Ambac Assurance often is the control party as a result of insuring the transaction’s senior class or tranche. The control party may direct specified parties, usually the trustee, to take or not take certain actions following contractual defaults or trigger events. Control rights and the scope of direction and remedies vary considerably among our insured transactions. Because Ambac Assurance is party to and/or has certain rights in documents supporting transactions in the insured portfolio, Ambac Assurance frequently receives requests for amendments, waivers and consents (“AWCs”). As discussed below under “Credit Risk Management,” Ambac Assurance’s risk management personnel review, analyze and process all requests for AWCs. As a part of the Segregated Account Rehabilitation Proceedings, the Rehabilitation Court enjoined parties to preserve Ambac’s control rights that could otherwise have lapsed or been compromised.

Surveillance for collateral dependent transactions, including, but not limited to, residential mortgage-backed securities (“RMBS”), asset-backed securities (“ABS”) and student loan transactions, focuses on review of the underlying asset cash flows and, if applicable, the performance of servicers or collateral managers. Ambac Assurance generally receives periodic reporting of transaction performance from issuers or trustees. Risk analysts review these reports to monitor performance and, if necessary, seek legal or accounting advice to assure that reporting and application of cash flows comply with transaction requirements.

Proactive credit remediation can help to reduce exposure and/or reduce risk in the insured portfolio by securing rights and remedies, both of which help to mitigate losses in the event of default. The emphasis on reducing risk is centered on reducing enterprise-wide exposure on a prioritized basis.

Cross-functional teams have been established by senior risk managers in PRM to promote the active mitigation and/or targeted remediation of the insured portfolio. Examples of such teams include teams of professionals focused on (i) the review and enforcement of contractual representations and warranties in RMBS policies, (ii) RMBS servicing oversight and transfer and (iii) the analysis and prioritization of policies to target and execute risk reduction and commutation strategies. The establishment and purview of cross-functional teams is targeted to address our highest risk exposures. Members of such teams work with both internal and external experts in the pursuit of risk reduction on all fronts.

The RMBS servicing oversight team focuses on servicer oversight and remediation. Analysts monitor the performance of servicers through a combination of (i) regular reviews of servicer performance; (ii) compliance certificates received from servicer management; (iii) independent rating agency information; (iv) a review of servicer financial information; and (v) onsite servicing diligence. Servicer performance reviews typically include a review of collateral performance, including comparisons against benchmarks, as well as the processes of collection, default management, and loss mitigation. Ambac Assurance may require a back-up servicer or require “term-to-term” servicing which provides for limited, renewable servicing terms in order to provide greater flexibility regarding the servicing arrangements of a particular transaction.

In some transactions, Ambac Assurance has the right to direct a transfer of servicing to an alternative servicer, subject to certain conditions. The decision to exercise this right is made based on various factors, including an assessment of the performance of the existing servicer as outlined above, and an assessment of whether a transfer of servicing may improve the performance of the collateral and reduce risk to Ambac Assurance. Ambac Assurance assesses potential transferee servicers through on-site servicer reviews and reviews of servicer financial information. Accordingly, Ambac Assurance has developed relationships with preferred servicers in the residential mortgage backed sector. Preferred servicers are selected through a formalized servicer review process that determines, among other key factors, the servicer’s ability and willingness to actively manage intense and proven loss mitigation activities on RMBS. Ambac Assurance may decide to exercise its rights to direct the transfer of servicing to a preferred servicer. The transfer of servicing is done with the objectives of (i) minimizing losses and distress levels by deploying targeted and enhanced loss mitigation

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programs; (ii) increasing visibility to Ambac Assurance of all servicing activities that impact overall deal performance; and (iii) better aligning the servicer’s financial interest to the performance of the underlying deal through the utilization of performance based incentives. Ambac Assurance believes that the improved loss mitigation activities, alignment of interests and close monitoring of the preferred servicers constitute credible means of minimizing risks and losses related to selected Ambac Assurance insured RMBS.

A team of professionals has also been established to focus on recoveries from sponsors where Ambac Assurance believes that a material breach of representations and warranties has occurred with respect to certain RMBS policies. The team monitors monthly performance of the RMBS insured portfolio and uses criteria to determine which transactions to pursue with regard to such recoveries. The team engages experienced consultants to perform the re-underwriting of loan files and consult with internal and external legal counsel with regard to loan putbacks as well as settlement and litigation strategies (refer to Note 8 to the Consolidated Financial Statements included in Part II, Section 8 of this Form 10–K for further discussion on this topic).

The risk restructuring group focuses on the analysis, implementation and execution of commutation and related claims reduction or defeasance strategies primarily for policies allocated to the Segregated Account. Analysts evaluate the estimated timing and severity of projected policy claims as well as the potential impact of other loss mitigation strategies in order to target and prioritize policies, or portions thereof, for commutation, refinancing, bond purchase (of securities guaranteed by Ambac Assurance), or other claims reduction or defeasance strategies. For targeted policies, analysts will engage with bondholders, issuers and other economic stakeholders to negotiate, structure, and execute such strategies.

Credit Risk Management

CRM manages the decision process for all material matters that affect credit exposures within the insured portfolio. While PRM is responsible for the credit analysis and the recommendation and execution of credit remediation strategies, CRM provides a forum for independent assessments and sign-offs and drives consistency and timeliness. The scope of credit matters under the purview of CRM includes material amendments, waivers and consents, remediation plans, credit review scheduling, adverse credit classification and below investment grade rating designations, adversely classified credit reviews, sector reviews, and overall portfolio review. The decision process may involve a review of structural, legal, political and credit issues and also includes determining the proper level of approval, which varies based on the nature and materiality of the matter. Please refer to Note 2 to the Consolidated Financial Statements in Item 8 of this Form 10-K for further discussion of the various credit classifications.

Adversely Classified Credit Review

Credits that are either in default or have developed problems that eventually may lead to a default are tracked closely by the appropriate PRM surveillance team and discussed at meetings with CRM. Adversely classified credit meetings include members of CRM, PRM surveillance and legal analysts, as necessary. As part of the review, relevant information, along with the plan for corrective actions and a reassessment of the credit’s rating and credit classification is considered. Internal and/or external counsel generally review the documents underlying any problem credit and, if applicable, an analysis is prepared outlining Ambac Assurance’s rights and potential remedies, the duties of all parties involved and recommendations for corrective actions. Ambac Assurance also meets with relevant parties to the transaction as necessary. The review schedule for adversely classified credits is tailored to the remediation plan to track and prompt timely action and proper internal and external resourcing. A summary of developments regarding the adversely classified credits and credit trends is also provided to Ambac’s and Ambac Assurance’s Board of Directors no less than on a quarterly basis.

The insured portfolio contains exposures that are correlated and/or concentrated. Ambac’s surveillance includes identifying these types of exposures and identifying the risks that would or could trigger credit

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deterioration across the related exposures. When such risks occur, adverse credit classification may be warranted across many of the correlated and/or concentrated exposures. This is the case with student loans and RMBS, for example. In the past, our not for profit healthcare and our leveraged lease exposures experienced periods of stress arising from their concentrated and/or correlated risks. In the future, Ambac’s portfolio may be subject to similar credit deterioration arising from concentrated and/or correlated risks. Examples of other such risks that could impact our portfolio, and that our surveillance is designed to monitor include the impact of potential municipal bankruptcy contagion or large scale domestic military cutbacks on our military housing portfolio or event risk such as natural disasters or other regional stresses. Most such risks cannot be predicted, and may materialize unexpectedly or develop rapidly. Although our surveillance allows us to connect the event and stress to the related exposures and assign an adverse credit classification and estimate losses across the affected credits, when necessary, we may not have adequate resources or contractual rights and remedies to mitigate loss arising from such risks.

Amendment, Waiver and Consent Review / Approval

The decision to approve or reject AWCs is based upon certain credit factors, such as the issuer’s ability to repay the bonds and the bond’s security features and structure. Members of Ambac Assurance’s PRM risk management group review, analyze and process all requests for AWCs. All AWCs are initially screened for materiality in the surveillance groups. Non-material AWCs require the approval of at least a PRM surveillance analyst and a portfolio risk manager. Material AWCs are within the purview of CRM, as noted above. For material AWCs, CRM has established minimum requirements that may be modified to require more or varied approvals depending upon the matter’s complexity, size or other characteristics.

Ambac Assurance assigns internal credit ratings to individual exposures as part of the AWC process and at surveillance reviews. These internal credit ratings, which represent Ambac Assurance’s independent judgments, are based upon underlying credit parameters consistent with the exposure type.

Investment Securities

Ambac manages credit risk associated with its investment portfolio through adherence to specific investment guidelines. These guidelines establish limits based upon single risk, asset type, and minimum credit rating standards. Additionally, senior credit personnel monitor the portfolio on a continuous basis. Credit monitoring of the investment portfolio includes procedures on residential mortgage-backed securities consistent with those utilized to assess the risk of our insured RMBS exposures.

Derivatives

Credit risks relating to derivative positions primarily concern the default of a counterparty. Counterparty default exposure on derivatives (other than credit derivatives) is mitigated through the use of industry standard collateral posting agreements. For counterparties subject to such collateral posting agreements, collateral is posted when a derivative counterparty’s credit exposure exceeds contractual limits. Derivative contracts entered into with financial guarantee customers are not subject to collateral posting agreements. Credit risk associated with such customer derivatives, including credit derivatives, is managed through the financial guarantee portfolio risk management processes described above. In some cases, derivatives between Ambac and financial guarantee customers are placed through a third party financial intermediary and similarly do not require collateral posting. These transactions include structural mechanisms such as separate trust accounts to mitigate credit exposure to the intermediary.

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Reinsurance

Ambac Assurance has reinsurance in place pursuant to surplus share treaty and facultative agreements. To minimize its exposure to losses from reinsurers, Ambac Assurance (i) monitors the financial condition of its reinsurers; (ii) is entitled to receive collateral from its reinsurance counterparties in certain reinsurance contracts; and (iii) has certain cancellation rights that can be exercised by Ambac Assurance in the event of rating agency downgrades of a reinsurer (among other events and circumstances). Ambac Assurance held letters of credit and collateral amounting to approximately $153.1 million from its reinsurers at December 31, 2013. As of December 31, 2013, the aggregate amount of insured par ceded by Ambac Assurance to reinsurers under reinsurance agreements was $18,598 million, with the largest reinsurer accounting for $16,617 million or 8.4% of gross par outstanding at December 31, 2013. The following table represents the percentage ceded to reinsurers and reinsurance recoverable at December 31, 2013 and the reinsurers’ rating levels as of February 28, 2014:

Financial Guarantees in Force

Financial guarantee products were sold in three principal markets: U.S. public finance, U.S. structured finance and asset-backed and international finance. The following table provides a breakdown of guaranteed net par outstanding by market sector at December 31, 2013 and December 31, 2012. Guaranteed net par outstanding includes the exposures of policies that insure variable interest entities (“VIEs”) consolidated in accordance with ASC Topic 810, Consolidation. Guaranteed net par outstanding excludes the exposures of policies that insure bonds which have been refunded or pre-refunded:

Included in the above net par exposures at December 31, 2013 and 2012 are $2,776 and $11,282, respectively, of exposures that were executed in the form of credit derivatives, primarily collateralized loan exposures. See Part II, Item 7, “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and Item 8, “Financial Statements and Supplementary Data” for further discussion of credit derivative exposures.

U.S. Public Finance Insured Portfolio

Ambac’s portfolio of U.S. public finance exposures is $116,062 million, representing 65% of Ambac’s net par outstanding as of December 31, 2013 and a 19% reduction from outstandings at December 31, 2012. This

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reduction in exposure was mainly the result of lease and tax-backed terminations and normal exposure runoff. While Ambac’s U.S. public finance portfolio consists predominately of municipal issuances such as general and revenue obligations, and lease and tax-backed obligations of state and local government entities (including tax allocation bonds as described further below), the portfolio also comprises a wide array of non-municipal types of issuances, including financings for not-for-profit entities and transactions with public and private elements, which generally finance infrastructure, housing and other public interests.

Municipal issuance is generally supported directly or indirectly by the issuer’s taxing authority or by public sector fees and assessments which may or may not be specifically pledged. Risk factors in these transactions derive from the municipal issuer, including its fiscal management, politics, and economic position, as well as its ability and willingness to continue to pay their debt service while undergoing severe stress. Municipal bankruptcy, while still uncommon, has increased, exposing Ambac to the risk of liquidity claims and ultimate losses if issuers cannot successfully adjust their liabilities without impairing debt creditors.

Not-for-profit transactions are generally supported by the not-for-profit entities’ net revenues and may also include specific pledges, liens and/or mortgages. The entity typically serves a well-defined market and promulgates a public purpose mission. These transactions may afford Ambac contractual protections such as financial covenants and control rights in the event of issuer breaches and defaults. Risk factors in these transactions derive from the creditworthiness of the issuer, including but not limited to its financial condition, leverage, management, business mix, competitive position, industry and socioeconomic trends, government programs, etc. Examples of these types of transactions include not-for-profit hospitals and universities, charities, associations and museums.

Public/private transactions are generally structured to achieve their targeted public interest objective without direct support from the public sector. Some examples of this type of financing include affordable housing, private education, and privatized military and student housing. Protections within these financings provided to Ambac usually include the strength of the financed asset’s essentiality and public purpose, financial covenants, security and control rights. Risk factors include financial underperformance, event risk and a shift in the asset’s mission or essentiality. One example of this type of financing is U.S. military housing. Ambac insures approximately $6.2 billion of privatized military housing debt. The debt was issued to finance the construction and/or renovation of housing units for military personnel and their families on domestic U.S. military bases. Debt service is not directly paid or guaranteed by the U.S. Government. Rather, the bonds are serviced from the cash flow generated by rental payments deposited by the military directly into lockbox accounts as part of each service personnel’s Basic Allowance for Housing (BAH). Security for these transactions includes the BAH payments as well as an interest in the ground lease. Risk factors affecting these transactions include the ongoing base essentiality, military deployments, the U.S. government’s commitment to fund the BAH, the marketability/attractiveness of the on-base housing units versus off base housing, construction completion, environmental remediation, utility and other operating costs and housing management.

Certain issuers in our public finance portfolio have issued floating rate debt, which may introduce interest rate risk to Ambac Assurance. Refer to Auction Rate Securities and Variable Rate Demand Obligation Exposures below for further discussion. See Note 7 to the Consolidated Financial Statements, located in Part II, Item 8 of this Form 10-K for exposures by bond type.

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The table below shows Ambac’s ten largest U.S. public finance exposures, by repayment source, as a percentage of total financial guarantee net par outstanding at December 31, 2013:

U.S. Structured Finance and Asset-Backed Insured Portfolio

Ambac’s portfolio of U.S. structured finance exposures is $31,412 million, representing 17% of Ambac’s net par outstanding as of December 31, 2013 and a 26% reduction from outstandings at December 31, 2012. This reduction in exposure was the result of terminations of collateralized debt obligations (“CDO”) and normal exposure runoff. Insured exposures include securitizations of mortgage loans, home equity loans, student loans, leases, operating assets, CDOs, collateralized loan obligations (“CLO”), and other asset-backed financings, in each case where the majority of the underlying collateral risk is situated in the United States. Additionally, Ambac’s structured finance insured portfolio encompasses both secured and unsecured debt issued by investor-owned utilities. Included within the operating asset sector are securitizations of aircraft, shipping containers and rail car fleets. See Note 7 to the Consolidated Financial Statements, located in Part II, Item 8 in this Form 10-K for exposures by bond type as of December 31, 2013.

Structured finance exposures generally entail three forms of risks: (i) asset risk, which relates to the amount and quality of the underlying assets; (ii) structural risk, which relates to the extent to which the transaction’s legal structure and credit support provide protection from loss; and (iii) servicer risk, which is the risk that poor performance at the servicer or manager level contributes to a decline in cash flow available to the transaction. Ambac Assurance seeks to mitigate and manage these risks through its risk management practices.

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Structured securities are usually designed to help protect the investors and, therefore, the guarantor from the bankruptcy or insolvency of the entity that originated the underlying assets as well as from the bankruptcy or insolvency of the servicer of those assets. The servicer of the assets is typically responsible for collecting cash payments on the underlying assets and forwarding such payments, net of servicing fees, to a trustee for the benefit of the issuer. One potential issue is whether the sale of the assets by the originator to the issuer would be upheld in the event of the bankruptcy or insolvency of the originator and whether the servicer of the assets may be permitted or stayed from remitting to investors cash collections held by it or received by it after the servicer or the originator becomes subject to bankruptcy or insolvency proceedings. Another potential issue is whether the originator sold ineligible assets to the securitization transaction that subsequently deteriorated, and, if so, whether the originator has the willingness or financial wherewithal to meet its contractual obligations to repurchase those assets out of the transaction. Structural protection in a transaction, such as control rights that are typically held by the senior note holders, or guarantor in insured transactions, will determine the extent to which underlying asset performance can be influenced upon non-performance to improve the revenues available to cover debt service.

The following table presents the top five servicers by net par outstanding at December 31, 2013 for U.S. structured finance exposures:

The table below shows Ambac’s ten largest structured finance transactions, as a percentage of total financial guarantee net par outstanding at December 31, 2013:

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International Finance Insured Portfolio

Ambac’s portfolio of international finance insured exposures is $31,618 million, representing 18% of Ambac’s net par outstanding as of December 31, 2013 and a 17% reduction from outstandings at December 31, 2012. This reduction in exposure was the result of terminations of credit derivatives and asset-backed policies and normal exposure runoff. Ambac’s international finance insured exposures include a wide array of obligations in the international markets, including infrastructure financings, asset-securitizations, CDOs, utility obligations, and whole business securitizations (e.g. securitizations of substantially all of the operating assets of a corporation). In emerging markets, Ambac focused on future cash flow transactions from top tier issuers (structured transactions secured by U.S. Dollar and Euro cash flows generated from exports or payment remittances). See Note 7 to the Consolidated Financial Statements, located in Part II, Item 8 in this Form 10-K for exposures by bond type as of December 31, 2013.

When underwriting transactions in the international markets, Ambac considered the specific risks related to the particular country and region that could impact the credit of the issuer. These risks include the legal and political environment, capital markets dynamics, foreign exchange issues, and the degree of governmental support. Ambac continues to assess these risks through its ongoing risk management.

Ambac UK, which is regulated in the United Kingdom (“UK”), had been Ambac Assurance’s primary vehicle for directly issuing financial guarantee policies in the UK and the European Union (“EU”) with $25,564 million net par outstanding at December 31, 2013. Geographically, Ambac UK’s exposures are principally in the UK and continental Europe. In 2009, Ambac UK’s license to issue new business was curtailed by its regulator. The portfolio of insured exposures underwritten by Ambac UK is financially supported exclusively by the assets of Ambac UK and no capital support arrangements are in place with any other Ambac affiliate.

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The table below shows our ten largest international finance transactions as a percentage of total financial guarantee net par outstanding at December 31, 2013. Except where noted, all international finance transactions included in the table below are insured by Ambac UK:

Ambac UK, on behalf of Ambac Assurance and Ambac UK, manages exposures to thirteen issuers based in EU member countries (not including the UK). Two exposures, with net par outstanding of $1,087 million, are classified as sub sovereign/municipal exposures that may be impacted should there be continued adverse financial developments in the related countries of Italy or France. Eight exposures, with net par outstanding of $3,962 million, are classified as infrastructure/operating asset backed deals that are concession based where the underlying assets independently generate cashflow without operational reliance on the sovereign. Of the remaining three deals with net par outstanding of $240 million, two are CLOs that consist of various paper issued by corporates throughout the Euro zone and one is a structured insurance transaction.

Additional Insured Portfolio Information

CDO and CLO

CDO and CLO transactions involve the securitization of a portfolio of corporate bonds, corporate loan obligations and/or asset-backed securities. These transactions are included in either the US structured finance market or the international finance market dependent upon the geographic characteristics of the risk. The

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majority of these exposures are executed through credit derivatives. Ambac’s outstanding CDO and CLO exposures are comprised of the following types as of December 31, 2013 and December 31, 2012:

Average Life of Insured Portfolio

Ambac Assurance underwrote and priced financial guarantees based on the assumption that the guarantees would remain in force until the expected maturity of the underlying bonds. Ambac Assurance estimates that the average life of its guarantees on par in force at December 31, 2013 is approximately 12 years. The average life is determined by applying a weighted average calculation, using the remaining years to expected maturity of each guaranteed bond, and weighting them on the basis of the remaining net par guaranteed. Except for RMBS policies, no assumptions are made for future refundings or terminations of insured issues. RMBS policies incorporate assumptions on expected voluntary and involuntary prepayments over the remaining life of the insured obligation.

Issue Size

Ambac Assurance’s financial guarantee exposure in the U.S. public finance market reflects the historical participation across the whole range of deal sizes including those with an original par amount of less than $50 million. U.S. structured finance and international finance transactions generally involved larger transaction sizes. The following table sets forth the distribution of Ambac’s guaranteed portfolio as of December 31, 2013 with respect to the current size of each guaranteed issue:

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Ratings Distribution

The following tables provide a rating distribution of guaranteed total net par outstanding based upon internal Ambac Assurance credit ratings at December 31, 2013 and December 31, 2012 and a distribution by bond type of Ambac Assurance’s below investment grade net par exposures at December 31, 2013 and December 31, 2012. Below investment grade is defined as those exposures with a credit rating below BBB-:

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The decrease in below investment grade exposures are primarily due to (i) reductions to residential mortgage-backed securities during the year as a result of both voluntary prepayments by issuers and claims presented to Ambac Assurance; (ii) maturity of a portion of an international airport exposure resulting in an overall improvement in the credit quality of the remaining exposures; and (iii) principal payments on student loans (including commutation payments by Ambac), partially offset by an increase in certain public finance tax-backed obligations.

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U.S. residential mortgage-backed securities exposure

Ambac has exposure to the U.S. mortgage market primarily through direct financial guarantees of RMBS, including transactions that contain risks to first and second liens. The following tables provide, by vintage and type current net par outstanding of Ambac’s U.S. RMBS book of business:

Student Loans

Ambac Assurance’s student loan portfolio consists of credits collateralized by (i) federally guaranteed loans under the Federal Family Education Loan Program (“FFELP”) and (ii) private student loans. Whereas FFELP loans are guaranteed for a minimum of 97% of defaulted principal and interest, private loans have no government guarantee and, therefore, are subject to credit risk as with other types of unguaranteed credits. Due to the failure

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of the auction rate markets, the interest rates on some student loan securities have increased significantly to punitive levels pursuant to the transaction terms. Such increases, along with high levels of student loan defaults, have caused the collateralization ratio in these transactions to deteriorate on an accelerated basis due to negative excess spread and/or the use of principal receipts to pay current interest.

Student loan net par outstanding on Ambac insured obligations:

Collateral for the For-Profit Issuers consists of private loans which do not have any federal guarantee as to defaulted principal and interest. Collateral for the Not-For-Profit Issuers consists of both FFELP and private student loans. For the Not-For-Profit student loan portfolio, approximately 72% of the collateral backing student loan trusts consists of private loans while the remaining 28% consists of FFELP loans. Private loan defaults have been on the rise since the beginning of the financial crisis in 2007. Elevated unemployment rates, combined with high student loan debt levels will continue to put pressure on borrower’s ability to pay their loans.

The following table represents the student loan net par outstanding by underlying debt-type on Ambac insured obligations:

All of the Auction Rate debt is paying interest at the maximum auction rate or the “penalty rate” pursuant to the transaction documents, reflecting both the failure of the auction rate market as well as the deteriorating credit ratings of the deals. These rates are putting negative pressure on excess spread and credit enhancement in transactions and this, in many cases, is causing an erosion of equity. This impact has been offset modestly by the current low interest rate environment.

The current capital markets and rating agency assumptions for new private loan transactions require a significant amount of equity which makes refinancing of Ambac insured transactions backed by private loans difficult for issuers. As such, we do not expect that our private loan exposure, particularly For-Profit Issuers, will be significantly reduced via refinancing in the near term. Transactions collateralized by FFELP loans are increasingly more likely to be refinanced if issuers raise enough equity through auction rate redemptions or otherwise to meet the overcollateralization required from the rating agencies.

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Auction Rate Securities (“ARS”) and Variable Rate Demand Obligations (“VRDO”):

Debt securities issued in the bond market include fixed and variable rate bonds. Included within the variable rate bond category are ARS and VRDO issued in the United States. The following table sets forth Ambac Assurance’s financial guarantee net par exposure outstanding, by bond type, relating to such variable rate securities at December 31, 2013 and December 31, 2012:

ARS are sold through a Dutch auction, which is a competitive bidding process used to determine rates on each auction date. VRDO are long-term bonds that bear a floating interest rate and that provide investors the option to tender or put securities back to the issuer or the liquidity provider at any time with appropriate notice. Additionally, there are certain mandatory events that require all bondholders to tender their VRDO to the issuer or liquidity provider. The interest rate resets daily or weekly, depending upon the security.

VRDO are typically supported by a liquidity facility in the form of a standby bond purchase agreement (“Standby Bond Purchase Agreement”), usually provided by a commercial bank (“Liquidity Provider”). If the remarketing agent is unable to remarket all tendered VRDO, the Liquidity Provider is required to purchase such VRDO at the purchase price, subject to limited conditions precedent, thus providing liquidity to investors. While held by the Liquidity Provider, VRDO bear interest at a rate determined under the Standby Bond Purchase Agreement, often based on the Prime Rate or LIBOR plus a spread (the “Bank Rate”). During such time, the remarketing agent remains obligated to continue to try to remarket the VRDO held by the Liquidity Provider. Many Standby Bond Purchase Agreements provide that, after the Liquidity Provider has held the VRDO for a specified time period, the issuer or other obligor is required to cause such VRDO to be redeemed prior to maturity, either: in periodic installments over a predetermined number of years, typically from three to five (the “Term-Out”); or with available funds as defined in the transaction documents; or in a single lump sum at the end of three to five years. Other Standby Bond Purchase Agreements do not contain a Term-Out. For VRDO insured by Ambac Assurance, Ambac Assurance typically endorsed its insurance policy to cover interest at the Bank Rate. For VRDO insured by Ambac Assurance that contain a Term-Out, Ambac often endorsed its insurance policy to cover the required redemptions in accordance with the Term-Out schedule (though not any acceleration of the VRDO maturity ahead of the Term-Out schedule).

Issuers have been working toward reducing their debt service costs for ARS and VRDO transactions. The most prevalent ways have been; (i) refunding or refinancing the obligations and issuing new bonds or other debt structures; (ii) entering into interest rate swaps to synthetically fix their interest rates; (iii) purchasing direct-pay letters of credit from other financial institutions; (iv) amending their liquidity facilities to address investor liquidity concerns; or (v) converting the bonds to fixed rate (to maturity or for a shorter period of time).

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For Ambac Assurance insured ARS and VRDO transactions that have been unable to refinance, the higher debt service costs have resulted in decreased debt service coverage ratios and/or the erosion of first loss and/or other credit enhancements that are subordinate to Ambac Assurance’s risk position (such as excess spread). Ambac continues to actively review the credit implications of this additional issuer stress and its impact to our internal credit ratings and loss reserves as necessary.

Tax Allocation Bonds

Ambac Assurance has $5,819 million net exposure to debt issued by California redevelopment agencies (“RDAs”) in its public finance portfolio, including $457 million that is below investment grade. Certain municipalities established RDAs to fund redevelopment projects. Debt issued by RDAs is principally secured by incremental property tax revenues above a designated assessed valuation (“AV”) level. The credit deterioration in our underperforming exposures arises from AV declines, and in some cases, from disputes arising among some or all of the RDA’s successor agency, and the municipality, county and State regarding entitlement to revenues and properties following the State’s dissolution of RDAs in December 2011. Additionally, although the RDA successor agencies continue to be entitled to the pledged revenues and assets and remain obligated to service RDA debt, we may be subject to liquidity claims due to timing mismatches between tax receipts and debt service payments. While we believe the above credit and liquidity risks will be contained, there can be no certainty these or other risks, and therefore our risk of loss, will not increase as the new law is enacted and its guidelines promulgated and AVs remain stressed.

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