PART I

the Segregated Account Rehabilitation Plan, as amended, the interim payment percentage (“IPP”) for permitted policy claims increased from 25% to 45% with effect from July 21, 2014. As with previously permitted policy claims, the remaining portion of the unpaid permitted policy claims (in this case, 55% ) will remain outstanding as Deferred Amounts (as defined in the Segregated Account Rehabilitation Plan) and, subject to the adjustment for Undercollateralized Bonds (as defined in the Segregated Account Rehabilitation Plan), will accrue interest at 5.1% per annum. These Deferred Amounts, together with interest thereon, may be paid from time to time in the future at the sole discretion of the Rehabilitator.

Ambac Assurance is evaluating the possibility of entering into one or more transactions to improve the financial condition of Ambac Assurance which may, subject to OCI approval, lead to the conclusion of the Segregated Account Rehabilitation Proceedings. In pursuing this objective, Ambac Assurance is considering the possibility of monetizing certain assets, restructuring or exchanging certain outstanding debt and insurance obligations, and/or commuting or reducing insured exposures. Ambac Assurance is also discussing with OCI potential options for addressing outstanding Segregated Account and other obligations. From time to time Ambac Assurance has also discussed, and intends to continue discussing, with counterparty creditors and OCI a potential transaction pursuant to which outstanding Deferred Amounts and surplus notes, in each case including accrued interest, would be exchanged for or satisfied by indebtedness, or other instruments which may include securities, and cash or other assets. In evaluating potential transactions, we understand that OCI intends to consider, among other things, their impact on the company and policyholders, and we intend to consider, among other things, their impact on the company and our stakeholders, including, in each case, their legal, regulatory and tax implications.  

However, Ambac Assurance has not reached any agreement on the terms of any such transaction, and we cannot provide any assurance that any such transaction will be consummated by Ambac Assurance in the future, or if it is, as to the timing, terms or conditions of any such transaction, or as to whether it could lead to the conclusion of the Segregated Account Rehabilitation Proceedings. Any such transaction proposed by Ambac Assurance would be subject to the prior approval of the board of directors of Ambac Assurance, OCI and the Rehabilitation Court and may require third-party consents, which may not be obtained. OCI has not indicated a course of action to address Segregated Account or other obligations or to conclude the Segregated Account Rehabilitation Proceedings. As stated in the Supplement (as defined below), the goal of the SDC (as defined below) is to provide additional directional guidance regarding the status of the Segregated Account rehabilitation during the first quarter of 2017, barring any unforeseen developments that might impede that effort. The terms, conditions, and timing of a potential conclusion of the Segregated Account Rehabilitation Proceedings are in the sole discretion of OCI, and subject to the approval of the Rehabilitation Court. This discretion includes the authority to address Segregated Account obligations without the agreement of Ambac Assurance or its board of directors. Moreover, even if the Segregated Account Rehabilitation Proceedings could be brought to a successful conclusion, there can be no assurance that any level of capital deemed sufficient by OCI to permit such conclusion will be sufficient to cover all future losses, whether currently anticipated or unanticipated.

On July 12, 2016, the Special Deputy Commissioner ("SDC") for the Segregated Account met with policy beneficiaries and holders of surplus notes of Ambac Assurance and the Segregated Account during which the SDC stated (i) that at present, the Rehabilitator does not have any plans to increase the interim payment percentage (“IPP”) on Segregated Account policy claims, commenting that the Rehabilitator and his advisors would need to feel highly confident that any change to the IPP would be sustainable and fair to all policyholders; (ii) that the Rehabilitator reserves the right to amend the Segregated Account Rehabilitation Plan or take such other action as he deems necessary or appropriate to adjust the rate of accretion on Deferred Amounts from time to time based on such factors as he considers relevant and, as such, the accretion rate remains under review; and (iii) his objective of seeking an exit of the Segregated Account from rehabilitation, and further stated that although his preferred goal would be to achieve an exit from rehabilitation through a consensual plan, he would advise the Rehabilitator to use all tools available to accomplish a successful and durable conclusion that enhances Ambac Assurance's long-term claims-paying ability.

On December 16, 2016, the Rehabilitator filed with the Rehabilitation Court a supplement to his 2016 Annual Report dated June 1, 2016 relating to the Segregated Account Rehabilitation Proceedings (the “Supplement”). In the Supplement, the Rehabilitator reiterated his goal of achieving a successful and durable conclusion to the Segregated Account Rehabilitation Proceedings. The Rehabilitator also stated in the Supplement that at the present time and absent further actions, Ambac Assurance has insufficient capital to demonstrate to the satisfaction of the Rehabilitator that the Segregated Account Rehabilitation Proceedings could be concluded and leave Ambac Assurance with sufficient financial resources to meet all policy obligations, as projected by the Rehabilitator (in his sole discretion) under a varying range of base and stress case scenarios. The Rehabilitator further stated in the Supplement that given such requirements, any transaction facilitating the conclusion of the Segregated Account Rehabilitation Proceedings will need to provide for an increase in Ambac Assurance’s existing surplus capital, as determined and defined by OCI in its sole discretion. We cannot provide assurance that the terms of any possible transaction will satisfy OCI or the Rehabilitator that Ambac Assurance has, or will have, sufficient capital to meet all policy obligations after the conclusion of the Segregated Account Rehabilitation Proceedings.

The execution of Ambac’s strategy to actively run off Ambac Assurance and its subsidiaries 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. The Rehabilitator's authority includes, but is not limited to, sole discretion over the rate at which the Segregated Account pays claims and the accretion rate on Deferred Amounts. 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 by or in respect of Ambac Assurance. Accordingly, oversight by the Rehabilitator could impair Ambac’s ability to execute certain of its strategies. Opportunities for transaction terminations, policy commutations, settlements and restructurings also 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 counterparty specific factors. Ambac Assurance's ability to

commute policies or purchase certain investments may also be limited by available liquidity.

Refer to Note 1. Background and Business Description to the Consolidated Financial Statements included in Part II, Item 8 in this Form 10-K, for more information on the Segregated Account and the Segregated Account Rehabilitation Proceedings.

Although we are exploring selective business transactions for Ambac, no assurance can be given that we will be able to execute the acquisition or development of any new businesses or assets. In addition, there can be no assurance that we will be able to obtain the financial and other resources that may be required to finance the acquisition or development of new businesses or assets that may permit utilization of Ambac’s net operating loss carry-forwards. 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 highly speculative.

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 and its wholly owned subsidiary Ambac Assurance UK Limited (“Ambac UK”), both of which have been in runoff since 2008. Insurance policies insured by Ambac Assurance and Ambac UK generally guarantee payment when due of the principal and interest on the obligations 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 the financial condition of Ambac Assurance and Ambac UK has prevented these companies 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 and by the terms of the Settlement Agreement, dated as of June 7, 2010 (the "Settlement Agreement"), by and among Ambac Assurance, Ambac Credit Products LLC (“ACP”), Ambac and certain 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 "Dividend Restrictions, Including Contractual Restrictions" below and Note 8. Insurance Regulatory Restrictions to the Consolidated Financial Statements included in Part II, Item 8 in this Form 10-K, for more information on dividend payment restrictions.

Ambac Assurance and its subsidiaries have been working toward reducing uncertainties within its insured portfolio through active monitoring and management of key exposures such as Puerto Rico, asset-backed securities (including residential mortgage-backed (RMBS) and student loans) and municipal entities with stressed financial conditions. Additionally, Ambac Assurance and its subsidiaries are actively prosecuting legal claims (including RMBS related lawsuits), managing the regulatory framework and other aspects of the Segregated Account, seeking to optimize capital allocation in a challenging environment that includes long duration obligations and attempting to retain key employees.

Ambac’s Financial Services business segment is operated by subsidiaries of Ambac Assurance. This segment provides financial and investment products, including investment agreements, funding conduits and interest rate swaps, principally to the clients of its financial guarantee business. The Financial Services business also maintains interest rate derivatives to mitigate exposure to floating rate insured obligations in the Financial Guarantee segment. Ambac Assurance insured all of the obligations of its financial services subsidiaries. The financial services businesses are in runoff, which is being effectuated by transaction terminations, settlements, assignments and scheduled amortization of contracts.

Enterprise Risk Management

The Company's policies and procedures relating to risk assessment and risk management are overseen by its Board of Directors. The Board takes an enterprise-wide approach to risk management oversight that is designed to support the Company's business plans at a reasonable level of risk. A fundamental part of risk assessment and risk management is not only understanding the risks the Company faces and what steps management is taking to manage those risks, but also understanding what level of risk is appropriate for the Company. The Board of Directors annually reviews the Company's business plan, factoring risk management into account. It also approves the Company's risk appetite statement, which articulates the Company's tolerance for risk and describes the general types of risk that the Company accepts or attempts to avoid.

While the Board of Directors has the ultimate oversight responsibility for the risk management process, various committees of the Board also have responsibilities related to risk assessment and risk management, and management has responsibility for managing the risks to which the Company is exposed and reporting on such matters to the Board of Directors and applicable Board committees.

The Audit Committee oversees the management of risks associated with the integrity of Ambac’s financial statements and its compliance with legal and regulatory requirements. In addition, the Audit Committee discusses policies with respect to risk assessment and risk management, including major financial risk exposures and the steps management has taken to monitor and control such exposures. The Audit Committee reviews with management, internal auditors, and external auditors Ambac's accounting policies, our system of internal controls over financial reporting, and the quality and appropriateness of disclosure and content in the financial statements and other external financial communications.

The Compensation Committee oversees the management of risk primarily associated with our ability to attract, motivate and retain quality talent, particularly executive talent, compensation structures that might lead to undue risk taking, and disclosure of our executive compensation philosophies, strategies and activities.

The Governance and Nominating Committee oversees the management of risk primarily associated with Ambac’s ability to attract and retain quality directors, Ambac’s corporate governance programs and practices and our compliance therewith. Additionally, the Governance and Nominating Committee oversees the processes for evaluation of the performance of the Board, its committees and management each year and considers risk management effectiveness as part of their evaluation. The Governance and Nominating Committee also performs oversight of the business

ethics and compliance program, and reviews compliance with Ambac’s Code of Business Conduct.

The Strategy and Risk Policy Committee oversees the management of risk and risk appetite primarily with respect to strategic plans and initiatives, oversight of Ambac’s capital structure, financing and treasury matters and oversight of management's process for the identification, evaluation and mitigation of Ambac’s financial and commercial-related risks.

The full Board also receives quarterly updates from Board committees, and the Board provides guidance to individual committee activities as appropriate.

In order to assist the board of directors in overseeing Ambac’s risk management, Ambac uses enterprise risk management, a company-wide initiative that involves the Board of Directors, management and other personnel in an integrated effort to identify, assess and manage risks that may affect the Company’s ability to execute on its corporate strategy and fulfill its business objectives. These activities entail the identification, prioritization and assessment of a broad range of risks (e.g., credit, financial, legal, liquidity, market, model, operational, regulatory and strategic), and the formulation of plans to manage these risks or mitigate their effects.

The Enterprise Risk Committee (“ERC”) is a management committee which is comprised of senior level management responsible for assisting in the management of the Company’s risks on an individual and aggregate basis. The ERC produces the relevant risk management information for senior management, the Board of Directors and applicable Board committees.

Common Stock Restrictions

Ambac’s Amended and Restated Certificate of Incorporation limits voting and transfer rights of stockholders in significant ways. Article IV contains voting restrictions applicable to any person owning at least 10% of Ambac’s common stock so that such person (including any group consisting of such person and any other person with whom such person or any affiliate or associate of such person has any agreement, contract, arrangement or understanding with respect to acquiring, voting, holding or disposing of Ambac’s common stock) shall not be entitled to cast votes in excess of one vote less than 10% of the votes entitled to be cast by all common stock holders, except as otherwise approved by OCI.

There are substantial restrictions on the ability to transfer Ambac’s common stock set forth in Article XII of Ambac’s Amended and Restated Certificate of Incorporation. In order to preserve certain tax benefits, subject to limited exceptions, any attempted transfer of common stock shall be prohibited and void to the extent that, as a result of such transfer (or any series of transfers of which such transfer is a part), either (i) any person or group of persons shall become a holder of 5% or more of the Company’s common stock or (ii) the percentage stock ownership interest in Ambac of any holder of 5% or more of the Company’s common stock shall be increased (a “Prohibited Transfer”). These restrictions shall not apply to an attempted transfer if the transferor or the transferee obtains the written approval of Ambac’s Board of Directors to such transfer. A purported transferee of a Prohibited Transfer shall not be recognized as a stockholder of Ambac for any purpose whatsoever in respect of the securities which are the subject of the Prohibited Transfer (the “Excess Securities”). Until the Excess Securities are acquired by another person in a transfer that is not a Prohibited

Transfer, the purported transferee of a Prohibited Transfer shall not be entitled with respect to such Excess Securities to any rights of stockholders of Ambac, including, without limitation, the right to vote such Excess Securities and to receive dividends or distributions, whether liquidating or otherwise, in respect thereof, if any. Once the Excess Securities have been acquired in a transfer that is not a Prohibited Transfer, the securities shall cease to be Excess Securities. If the Board determines that a transfer of securities constitutes a Prohibited Transfer then, upon written demand by Ambac, the purported transferee shall transfer or cause to be transferred any certificate or other evidence of ownership of the Excess Securities within the purported transferee’s possession or control, together with any distributions paid by Ambac with respect to such Excess Securities, to an agent designated by Ambac. Such agent shall thereafter sell such Excess Securities and the proceeds of such sale shall be distributed as set forth in the Amended and Restated Certificate of Incorporation. If the purported transferee of a Prohibited Transfer has resold the Excess Securities before receiving such demand, such person shall be deemed to have sold the Excess Securities to Ambac’s agent and shall be required to transfer to such agent the proceeds of such sale, which shall be distributed as set forth in the Amended and Restated Certificate of Incorporation.

Available 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 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 email: ir@ambac.com. 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 2016 , 2015 and 2014 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 provided by Ambac Assurance and its subsidiaries. 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 also permit certain counterparties to assert mark-to-market termination claims under certain conditions; 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 obligor supporting the guaranteed obligation. In addition, insured transactions expose Ambac to indirect risks that may increase our overall risk, such as credit risk separate from, but correlated with, our direct credit risk, market, model, economic, natural disaster and mortality or other non-credit type risks.

Ambac Assurance derives financial guarantee revenues from: (i) premiums earned from insurance contracts, net of reinsurance; (ii) net investment income; (iii) fees from credit derivative transactions; (iv) net realized gains and losses from sales of investment securities; and (v) amendment and consent fees. Financial guarantee expenses include: (i) loss and commutation payments for credit exposures; (ii) loss-related expenses, including those relating to the remediation of problem credits; (ii) insurance intangible amortization and (iv) operating expenses. Premiums for financial guarantees were received either upfront 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. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included in Part II, Item 7 in this Form 10-K for further information.

Risk Management

The Asset Liability Management Committee (“ALCO”) is a management 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 the Risk Management Group. 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.

The Risk Management group is primarily responsible for the development, implementation and oversight of loss mitigation strategies, surveillance and remediation of the insured financial guarantee portfolio (including through the pursuit of recoveries in respect of paid claims and commutations of policies). 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 and other personnel provide 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. Background and Business Description to the Consolidated Financial Statements included in Part II, Item 8 in this Form 10-K, 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 any of its rights to alter or eliminate any of these risk management practices.

Ambac’s Risk Management group has an organizational structure designed around three primary areas of focus: Portfolio Risk Management and Analysis, Credit Risk Management and Loss Reserving and Analytics. The senior manager responsible for these groups reports directly to Ambac's Chief Executive Officer and regularly informs and updates the Audit Committees 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 ("PRM")

This group’s focus is on remediation, loss mitigation, risk reduction, restructuring and surveillance. 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. Restructuring or workout is the focused and active process of minimizing claims and maximizing recoveries typically following an event of default. The emphasis on reducing risk is centered on reducing enterprise-wide exposure on a prioritized basis.

PRM 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. 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. 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 and performance 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 and surveillance requirements. 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 and senior risk managers as part of the restructuring or workout process and discussed at regularly scheduled meetings with Credit Risk Management (see discussion following in “Credit Risk Management”). In some cases, PRM will engage restructuring or workout experts, attorneys and / or 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.

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 certain actions by other parties to preserve Ambac Assurance’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 ensure that reporting and application of cash flows comply with transaction requirements.

Cross-functional teams have been established, across PRM and other groups as necessary given the targeted strategy to promote active mitigation and remediation of losses associated with certain credits and sectors in 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 and (iii) the analysis and prioritization of policies with projected claims 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 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)  reviews 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 RMBS and other servicing to an alternative servicer, upon certain events and 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. In the case of RMBS, Ambac Assurance has developed relationships with preferred servicers. 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 where such rights are available. The transfer of servicing is done with the objectives of (i) minimizing losses and distress levels by deploying targeted and enhanced loss mitigation programs; (ii) increasing visibility to Ambac Assurance of all servicing activities that impact overall deal performance; (iii) better aligning the servicer’s financial interest to the performance of the underlying deal through the utilization of performance based incentives; and (iv) reducing the risk of servicer underperformance due to servicer financial difficulty.

Ambac Assurance believes that the improved loss mitigation activities, alignment of interests and close monitoring of servicers constitute credible means of minimizing risks and losses related to insured RMBS.

A team of professionals is focused on recoveries from sponsors where Ambac Assurance believes material breaches of representations and warranties have occurred with respect to certain RMBS policies.  The team engages with experienced consultants to perform the re-underwriting of loan files and consults with internal and external legal counsel with regard to loan putbacks as well as settlement and litigation strategies (refer to Note 7. Financial Guarantee Insurance Contracts to the Consolidated Financial Statements included in Part II, Item 8 in this Form 10-K for further discussion on this topic).

PRM focuses on the analysis, implementation and execution of commutation and related claims reduction or defeasance strategies for policies with projected claims. Analysts evaluate the estimated timing and severity of such 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, bond purchase, refinancing 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")

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 approvals and drives consistency and timeliness. Strategic level credit and restructuring issues may also involve the CEO and other executive management to augment the CRM process in the interest of achieving best outcomes. 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 CRM 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. Decisions that also have material asset, liability, and liquidity implications, such as commutations, bond purchases and refinancings may also require ALCO approval. Please refer to Note 2. Basis of Presentation and Significant Accounting Policies to the Consolidated Financial Statements included in Part II, Item 8 in 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 and legal, 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 adversely classified credits and credit trends is also provided to Ambac’s and Ambac Assurance’s Board of Directors no less than quarterly.

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 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, which have several correlations including those associated with consumer lending, unemployment and home prices. 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, when there were major changes to healthcare reimbursement programs especially Medicaid, or significant weakness in consumer and business travel, in the case of the former and the latter, respectively. 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 the impact of 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 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.

Loss Reserving and Analytics Group ("LRA")

LRA manages the quarterly loss reserving process for insured portfolio credits with projected policy claims. It also supports the development, operation and/or maintenance of various analytical models used in the loss reserving process as well as in other risk management functions. LRA will work together with PRM analysts responsible for a particular credit on the development, review and implementation of loss reserve scenarios and related analysis.

Financial Guarantees in Force

Financial guarantee products were sold in three principal markets: U.S. public finance, U.S. structured finance and international finance. The following table provides a breakdown of guaranteed net par outstanding by market sector at December 31, 2016 and 2015 . Net par exposures within the U.S. public finance market include capital appreciation bonds which are reported at the par amount at the time of issuance of the insurance policy. Guaranteed net par outstanding includes the exposures of policies that insure variable interest entities (“VIEs”) consolidated by Ambac. 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, 2016 and 2015 are $737 million and $971 million, 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.

Certain guaranteed bonds were issued as floating rate debt, including Auction Rate Securities and Variable Rate Demand Obligations, which may introduce interest rate risk to Ambac Assurance. Refer to Auction Rate Securities and Variable Rate Demand Obligation Exposures below for further discussion.

U.S. Public Finance Insured Portfolio

Ambac’s portfolio of U.S. public finance exposures is $45,062 million , representing 57% of Ambac’s net par outstanding as of December 31, 2016 and a 31% reduction from the amount outstanding at December 31, 2015 . This reduction in exposure was mainly due to normal exposure runoff in addition to early terminations (calls, refundings and pre-refundings). While Ambac’s U.S. public finance portfolio consists predominantly of municipal bonds such as general and revenue obligations and lease and tax-backed obligations of state and local government entities, the portfolio also comprises a wide array of non-municipal types of bonds, including financings for not-for-profit entities and transactions with public and private elements, which generally finance infrastructure, housing and other public interests. See Note

6. Financial Guarantees in Force to the Consolidated Financial Statements, included in Part II, Item 8 in this Form 10-K for exposures by bond type.

Municipal bonds are 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 its debt service. Municipal bankruptcies, while still relatively uncommon, have occurred, exposing Ambac to the risk of liquidity claims and ultimate losses if issuers cannot successfully adjust their liabilities without impairing 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, universities, associations and charities.

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 and may include financial covenants, collateral 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 $5.9 billion net par 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 in most cases by rental payments deposited by the military directly into lockbox accounts as part of each service personnel’s Basic Allowance for Housing (BAH). In small number of cases rental payments are also coming from civilians, including retired service personnel, living on a particular base. Collateral 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.

Puerto Rico

Ambac has exposure to Puerto Rico across several different issuing entities. Each has its own credit risk profile attributable to discrete revenue sources, direct general obligation pledges and general obligation guarantees. The following table shows Ambac's insured

exposure to each issuer segregated by whether such debt obligation is subject to the Priority Debt Provision or "clawback." Ambac has initiated litigation challenging the application of the "clawback" announced by Governor Padilla, Puerto Rico's former governor, on December 1, 2015. A description of Ambac's legal challenge is provided in Note 17. Commitments and Contingencies in the Consolidated Financial Statements, included in Part II, Item 8 in this Form 10-K.

Most Puerto Rico bonds insured by Ambac Assurance are not subject to acceleration. The Ambac-insured Puerto Rico Convention Center District Authority (Hotel Occupancy Tax) bonds may be accelerated only with the consent of, or at the direction of, Ambac Assurance. The Ambac-insured Puerto Rico Sales Tax Financing Corporation's Senior Sales Tax Revenue bonds may be accelerated only with the consent of Ambac Assurance, subject to the Ambac financial guaranty insurance policy being in full force and effe ct.

In November and December 2015, former Governor Padilla issued certain executive orders purporting to implement the Commonwealth Constitution’s Priority Debt Provision for Fiscal Year 2016, due to his claim that there are insufficient revenues to pay all appropriations for the year.  The executive orders called for the "clawback" of certain revenues that would otherwise have been transferred to the Puerto Rico Highways and Transportation Authority (“HTA”), the Puerto Rico Infrastructure Financing Authority (“PRIFA”) and the Puerto Rico Convention Center District Authority (“PRCCDA”) to be transferred instead for application to the Commonwealth’s public debt.  As a result, such revenues were not available to pay debt service owed by those entities, including on bonds insured by Ambac Assurance.  Ambac has filed a lawsuit in U.S. District Court, District of Puerto Rico, asserting that the executive orders and diversion of revenues violate the U.S. Constitution.  Refer to Note 17. Commitments and

Contingencies to the Consolidated Financial Statements included in Part II, Item 8 in this Form 10-K for a further discussion of this lawsuit.

In June 2016, the United States enacted the Puerto Rico Oversight, Management, and Economic Stability Act (“PROMESA”). Among other things, PROMESA provides for a temporary stay on certain litigation concerning the debt obligations of the Commonwealth and its instrumentalities. The federal district court overseeing various creditor lawsuits in the District of Puerto Rico has held that the PROMESA litigation stay applies broadly, and the U.S. Court of Appeals for the First Circuit has affirmed the district court's denial of one plaintiff's attempt to lift the litigation stay. These rulings may limit Ambac Assurance's ability to engage in certain aspects of loss mitigation in the short term. The litigation stay, which was originally

set to expire on February 15, 2017, has been extended until May 1, 2017.

On October 28, 2016, Ambac Assurance opted not to contest the application of the PROMESA litigation stay to its lawsuit challenging the "clawback" orders, while reserving the right to seek to lift the stay in the future. As a result, there may be additional delay in obtaining a ruling on the merits of the claims asserted in this lawsuit.

Since April 2016, the Commonwealth has been subject to an emergency moratorium, known as "Law 21," on debt payments of the Commonwealth and its instrumentalities. Beginning in April 2016, and culminating on June 30, 2016, former Governor Padilla issued additional executive orders under Law 21 declaring states of emergency at HTA, PRIFA, PRCCDA, and other Puerto Rico instrumentalities through January 31, 2017, and suspending payment obligations on bonds issued by those entities, including bonds insured by Ambac Assurance. Subsequent to the implementation of the moratorium, the Commonwealth defaulted on approximately $0.9 billion out of $2.0 billion of debt service due on July 1, 2016, including certain Puerto Rico bonds insured by Ambac Assurance. On January 29, 2017, current Governor Rosello signed the Financial Emergency and Fiscal Responsibility Act, which extends the emergency moratorium period until May 1, 2017, with an option to extend another three months until August 1, 2017.

PROMESA provides that laws such as Law 21 are not binding on any non-consenting creditor to the extent they prohibit the payment of principal or interest.  The practical effect of this provision is unknown and therefore Ambac is at risk to the ongoing execution, interpretation and ultimate enforcement of this provision.  PROMESA also provides that unlawful executive orders are preempted under PROMESA, but there is no procedure for determining whether a particular executive order is unlawful, creating uncertainty in general and with specific regards to how the preemption provision will be implemented towards Ambac’s exposures.

On October 7, 2016, certain holders of Puerto Rico’s GO bonds requested leave of court to file an amended complaint that, among other things, challenges the structure of the Puerto Rico Sales Tax Financing Corporations ("COFINA") and seeks injunctive relief requiring the sales and use tax proceeds securing the bonds issued by COFINA to be transferred to the Commonwealth treasury for payment of GO bonds.  On October 26, 2016, Ambac filed a motion to intervene in that lawsuit and argued that the proposed claims are subject to PROMESA’s litigation stay. The Court granted the GO plaintiffs’ motion to file an amended complaint on November 4, 2016. On February 17, 2017, the Court issued an opinion and order granting Ambac’s motion to intervene and denying the request to stay the litigation under PROMESA. The Court clarified that claims asserted under PROMESA, which could not have been commenced before the enactment of the statute, are not subject to the litigation stay. If successful, the GO plaintiffs’ challenge against COFINA,

and any similar claims that could be asserted by other plaintiffs in the future, could have a significant negative impact on Ambac’s liquidity, loss reserves and capital resources.

As noted above, PROMESA creates a new federal legislative framework for Puerto Rico.  It is untested and many provisions are unique.  There is inherent uncertainty and risk both generally and for Ambac’s exposures specifically regarding the interpretation and implementation of PROMESA.  Among other things, PROMESA contains provisions that may permit consensual and non-consensual restructurings of debt obligations of the Commonwealth and its instrumentalities. PROMESA also confers significant powers and responsibilities on the oversight board created thereunder (the “Oversight Board”). Among other things, the Oversight Board is required to certify any insolvency petitions that may be filed by Puerto Rico instrumentalities under Title III of PROMESA, any proposed plans of adjustment in such proceedings, and any voluntary restructuring agreement among creditors under Title VI of PROMESA (which has the potential to bind non-consenting creditors). The Oversight Board is also required to approve fiscal plans and budgets submitted by the Commonwealth and monitor compliance with those plans and budgets, and to approve any debt issuances or modifications by the Commonwealth or its instrumentalities.  Ambac is unable to predict to what extent debt restructurings will be proposed or implemented under PROMESA, and how its insured obligations will fare in any such restructurings.  

On October 14, 2016, former Governor Padilla presented the Commonwealth’s Fiscal and Economic Growth Plan (“FEGP”) to PROMESA oversight board members.  The FEGP lays out various economic scenarios in which Puerto Rico incurs significant deficits over the next 10 years.  These range from $58.7 billion, if Puerto Rico loses Affordable Care Act money from the federal government in 2018 and other revenue shortfall assumptions, to $5.7 billion, if Puerto Rico excludes all debt service payments over the next 10 years in isolation.  These scenarios implied that significant cuts to debt service obligations are required in order to balance budgets and eliminate fiscal deficits.  The Oversight Board did not certify this FEGP prior to end of Governor Padilla's term in December 2016.

Current Governor Rosello has agreed to provide a proposed FEGP to the Oversight Board by February 28, 2017. The Oversight Board expects that the FEGP will be certified by March 31, 2017. The Oversight Board has requested that the proposed FEGP includes, among other things, $3 billion in cuts to healthcare, University of Puerto Rico and pensions, and $1.5 billion in revenue enhancements by Fiscal Year 2019. It is currently unclear what, if anything, the proposed FEGP will do to address the restructuring of debt obligations of the Commonwealth or its instrumentalities. However, any such restructuring proposal may include material cuts to payment of principal and interest on debts insured by Ambac Assurance.

U.S. Structured Finance Portfolio

Ambac’s portfolio of U.S. structured finance exposures is $16,951 million , representing 21% of Ambac’s net par outstanding as of December 31, 2016 and a 22% reduction from the amount outstanding at December 31, 2015 . This reduction in exposure was the result of normal exposure runoff, primarily related to residential mortgage-backed policies, in addition to terminations and commutations of student loan and asset backed policies. Insured exposures include securitizations of mortgage loans, home equity loans, student loans, leases, operating assets, collateralized debt obligations ("CDO"), 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. Included within the lease securitization sector are pooled aircraft and railcar transactions. Additionally, Ambac’s structured finance insured portfolio includes secured and unsecured debt issued by investor-owned utilities, structured insurance transactions and aircraft equipment trust certificates. See Note 6. Financial Guarantees in Force to the Consolidated Financial Statements, included in Part II, Item 8 included in this Form 10-K, for exposures by bond type as of December 31, 2016 .

Structured finance exposures generally entail three forms of risk: (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.

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.

International Finance Insured Portfolio

Ambac’s portfolio of international finance insured exposures is $17,333 million , representing 22% of Ambac’s net par outstanding as of December 31, 2016 and an 18% reduction from the amount outstanding at December 31, 2015 . This reduction in exposure was primarily the result of the strengthening of the US dollar, exposure runoff including reduction of certain aircraft leasing obligations and other policy terminations. Ambac’s international finance insured exposures include a wide array of obligations in the international markets, including infrastructure financings, asset-securitizations, utility obligations, and whole business securitizations (e.g. securitizations of substantially all of the operating assets of a corporation). Ambac no longer has insured exposure related to emerging markets. See Note 6. Financial Guarantees in Force to the Consolidated Financial Statements, included in Part II, Item 8 included in this Form 10-K, for exposures by bond type as of December 31, 2016 .

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 with $15,082 million net par outstanding in those markets at December 31, 2016 . 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.

Ambac does not guarantee any sovereign bonds of the above EU countries. However, the exposures classified as sub sovereign may be impacted should there be adverse financial developments in the EU. Those exposures classified as infrastructure/operating asset backed are concession based where the underlying assets independently generate cash flow without operational reliance on the sovereign. Of the below investment grade exposures, the investor-owned utilities (wind farm and mini hydro-electric plant) are undergoing restructuring processes designed to address their performance issues. The other below investment grade exposure is a road transaction, where performance has been poorer than anticipated due to lower than forecast traffic volumes, however performance is improving. Below investment grade is defined as those exposures with a credit rating below BBB-.

Brexit:

In a non-binding referendum on the United Kingdom’s (“UK”) membership in the European Union ("EU") in June 2016, a majority of those who voted approved the UK’s withdrawal from the EU. Withdrawal by the UK from the EU (“Brexit”) would occur after, or possibly concurrently with, a process of negotiation regarding the future terms of the UK’s relationship with the EU, which could result in the UK losing access to certain aspects of the single EU market and the global trade deals negotiated by the EU on behalf of its members. The Brexit vote and the perceptions as to the impact of the withdrawal of the UK may adversely affect business activity, political stability and economic conditions in the UK, the Eurozone, the EU and elsewhere. The economic outlook could be further adversely affected by (i) the risk that one or more other EU countries could come under increasing pressure to leave the EU, (ii) the risk of a greater demand for independence by Scottish nationalists or for

unification in Ireland, or (iii) the risk that the Euro as the single currency of the Eurozone could cease to exist. Any of these developments, or the perception that any of these developments are likely to occur, could have a material adverse effect on economic growth or business activity in the UK, the Eurozone, and the EU, and could result in the relocation of businesses, cause business interruptions, lead to economic recession or depression, and impact the stability of the financial markets, the availability of credit, political systems or financial institutions and the financial and monetary system. Consequently the medium and longer term impact on the UK generally, and Ambac UK specifically, is uncertain. 

The vote caused volatility in global stock markets and currency exchange rate fluctuations that resulted in the strengthening of the U.S. dollar against foreign currencies, particularly the British Pound and to a lesser extent the Euro. Ambac's wholly-owned UK subsidiary, Ambac UK, operates in the United Kingdom and the British Pound is its functional currency. Ambac UK conducts a portion of its business in currencies other than its functional currency, predominately the Euro and US Dollar. Refer to "Executive Summary - Foreign Currency Impacts" included in Part II, Item 7 in this Form 10-K, for more information on the economic and financial statement impact of such changes to foreign currency exchange rates.

Since the referendum vote, there has been a reduction in net par outstanding of insured exposures denominated in British Pounds and Euro of $2,678 million, primarily due to the strengthening of the US dollar. As of December 31, 2016 insured exposures denominated in British Pounds totaled £10,136 million and in Euros €1,831 million.

Additional Insured Portfolio Information

Average Life of Insured Portfolio

Ambac underwrote and priced financial guarantees based on the assumption that the guarantees would remain in force until the maturity of the underlying bonds. Ambac estimates that the average life of its guarantees on par in force at December 31, 2016 is approximately 11 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 non-contractual reductions, refundings or terminations of insured issues. RMBS policies incorporate assumptions on expected voluntary and involuntary prepayments over the remaining life of the insured obligation. The table below depicts amortization of existing guaranteed net par outstanding: