Cautionary Statement Pursuant to the Private Securities Litigation Reform Act of 1995

In this Quarterly Report, we have included statements that may constitute "forward-looking statements" within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Words such as "estimate," "project," "plan," "believe," "anticipate," "intend," "planned," "potential" and similar expressions, or future or conditional verbs such as "will," "should," "would," "could," and "may", or the negative of those expressions or verbs, identify forward-looking statements. We caution readers that these statements are not guarantees of future performance. Forward-looking statements are not historical facts but instead represent only our beliefs regarding future events, which, may by their nature be inherently uncertain and some of which may be outside our control. These statements may relate to plans and objectives with respect to the future, among other things which may change. We are alerting you to the possibility that our actual results may differ, possibly materially, from the expected objectives or anticipated results that may be suggested, expressed or implied by these forward-looking statements. Important factors that could cause our results to differ, possibly materially, from those indicated in the forward-looking statements include, among others, those discussed under "Risk Factors" in Part I, Item 1A of the 2008 Annual Report on Form 10-K and Part II, Item 1A of this Form 10-Q.

Any or all of management's forward-looking statements here or in other publications may turn out to be incorrect and are based on Ambac management's current belief or opinions. Ambac's actual results may vary materially, and there are no guarantees about the performance of Ambac's securities. Among events, risks, uncertainties or factors that could cause actual results to differ materially are: (1) difficult economic conditions, which may not improve in the near future, and adverse changes in the economic, credit, foreign currency or interest rate environment in the United States and abroad; (2) the actions of the U. S. Government, Federal Reserve and other government and regulatory bodies to stabilize the financial markets; (3) the risk that market risks impact assets in our investment portfolio or the value of our assets posted as collateral in respect of investment agreements and interest rate swap and currency swap transactions; (4) changes in Ambac's and/or Ambac Assurance's credit or financial strength ratings; (5) risks relating to the re-launch of Connie Lee as Everspan Financial Guarantee Corp.; (6) competitive conditions, pricing levels and reduction in demand for financial guarantee products;
(7) credit and liquidity risks due to unscheduled and unanticipated withdrawals on investment agreements; (8) inadequacy of reserves established for losses and loss expenses; (9) changes in capital requirements whether resulting from downgrades in our insured portfolio or changes in rating agencies' rating criteria or other reasons; (10) the risk that we may be required to raise additional capital, which could have a dilutive effect on our outstanding equity capital and/or future earnings; (11) our ability or inability to raise additional capital, including the risks that regulatory or other approvals for any plan to raise capital are not obtained, or that various conditions to such a plan, either imposed by third parties or imposed by Ambac or its Board of Directors, are not satisfied and thus potentially necessary capital raising transactions do not occur, or the risk that for other reasons the Company cannot accomplish any potentially necessary capital raising transactions; (12) credit risk throughout our business, including credit risk related to residential mortgage-backed securities and collateralized debt obligations ("CDOs") and large single exposures to reinsurers; (13) market spreads and pricing on insured CDOs and other derivative products insured or issued by Ambac; (14) the risk that holders of debt securities or counterparties on credit default swaps or other similar agreements seek to declare events of default or seek judicial relief or bring claims alleging violation or breach of covenants by Ambac or one of its subsidiaries; (15) default by one or more of Ambac Assurance's portfolio investments, insured issuers, counterparties or reinsurers; (16) Ambac's financial position and lack of financial flexibility, resulting principally from the uncertainty of Ambac Assurance's ability to pay dividends to Ambac without the consent of the office of the Commissioner of Insurance of the State of Wisconsin; (17) legislative and regulatory developments, including the Troubled Asset Relief Program and other programs under the

Emergency Economic Stabilization Act and other similar programs; (18) changes in accounting principles or practices relating to the financial guarantee industry or that may impact Ambac's reported financial results; (19) changes in expectations regarding future realization of gross deferred tax assets; (20) the risk of volatility in income and earnings, including volatility due to the application of fair value accounting, required under SFAS 133, to the portion of our credit enhancement business which is executed in credit derivative form, and due to the adoption of SFAS 163, which, among other things, introduces volatility in the recognition of premium earnings and losses; (21) the risk that our underwriting and risk management policies and practices do not anticipate certain risks and/or the magnitude of potential for loss as a result of unforeseen risks; (22) operational risks, including with respect to internal processes, risk models, systems and employees; (23) factors that may influence the amount of installment premiums paid to Ambac; (24) the risk of litigation and regulatory inquiries or investigations, and the risk of adverse outcomes in connection therewith, which could have a material adverse effect on our business, operations, financial position, profitability or cash flows; (25) the risk that reinsurers may dispute amounts owed us under our reinsurance agreements; (26) changes in tax laws; (27) other factors described in the Risk Factors section in Part I, Item 1A of the 2008 Annual Report on Form 10-K and Part II, Item 1A of this Form 10-Q and also disclosed from time to time by Ambac in its subsequent reports on Form 10-Q and Form 8-K, which are or will be available on the Ambac website at www.ambac.com and at the SEC's website, www.sec.gov; and (28) other risks and uncertainties that have not been identified at this time. Readers are cautioned that forward-looking statements speak only as of the date they are made and that Ambac does not undertake to update forward-looking statements to reflect circumstances or events that arise after the date the statements are made. You are therefore advised to consult any further disclosures we make on related subjects in Ambac's reports to the SEC.

Overview

Ambac Financial Group, Inc., headquartered in New York City, is a holding company incorporated in the state of Delaware. Ambac was incorporated on April 29, 1991. Ambac, through its subsidiaries, provides financial guarantees and financial services to clients in both the public and private sectors around the world. The long-term senior unsecured debt of Ambac is rated "BBB" with a negative outlook by Standard & Poor's Ratings Service, a division of the McGraw-Hill Companies, Inc. ("S&P"), and Caa1, with a developing outlook, by Moody's Investors Services, Inc. ("Moody's"). Ambac's activities are divided into two business segments: (i) Financial Guarantee and (ii) Financial Services.

Ambac has historically provided financial guarantee insurance for public and structured finance obligations through its principal operating subsidiary, Ambac Assurance Corporation ("Ambac Assurance"). Ambac Assurance's financial strength ratings were downgraded in April 2009 by Moody's to Ba3, with a developing outlook, and is rated A with a negative outlook from S&P. As a result of rating agency actions, as well as investor concern with respect to these actions, Ambac Assurance and its operating subsidiaries have been able to originate only a de minimis amount of new financial guarantee business since November 2007 and none in 2009.

Ambac Assurance has two financial guarantee insurance operating subsidiaries, Ambac UK and Everspan Financial Guarantee Corp. (previously Connie Lee Insurance Company) ("Everspan"). Ambac UK, insures a wide array of obligations in the international markets including infrastructure financings, asset-securitizations, CDOs, utility obligations, whole business securitizations (e.g. securitizations of substantially all of the operating assets of a corporation) and other obligations, generally within Western Europe. Everspan is a financial guarantee insurance company that was purchased by Ambac Assurance in 1997 and placed into runoff. Ambac Assurance is seeking to capitalize and reactivate Everspan which

would allow it to write new financial guarantee business in the U.S. public finance and regulated utility markets.

As an alternative to financial guarantee insurance, credit protection was provided by Ambac Credit Products LLC, a subsidiary of Ambac Assurance, in credit derivative format. Ambac Assurance insures the obligations of Ambac Credit Products under these transactions. These credit derivatives, which are privately negotiated contracts, provide the counterparty with credit protection against the occurrence of a specific event such as a payment default or bankruptcy relating to an underlying obligation. Upon a credit event, Ambac Credit Products is generally required to make payments equal to the difference between the scheduled debt service payment and the actual payment made by the issuer. In a small number of transactions, Ambac Credit Products is required to
(i) make a payment equal to the difference between the par value and market value of the underlying obligation or (ii) purchase the underlying obligation at its par value and a loss is realized for the difference between the par and market value of the underlying obligation. Substantially all of Ambac Credit Product's credit derivative contracts relate to structured finance transactions. As part of its refocused business strategy, Ambac decided to discontinue the execution of credit enhancement transactions in credit default swap format. However, Ambac may execute restructuring or hedging transactions in derivative format for purposes of mitigating losses and/or improving our position relative to existing credit exposures. See "Quantitative and Qualitative Disclosures About Market Risk" located in Item 3 of this Form 10-Q for further information about credit derivatives.

Through its financial services subsidiaries, Ambac provided financial and investment products including investment agreements, funding conduits, interest rate, currency and total return swaps, principally to its clients of the financial guarantee business. The obligations of the various subsidiaries which write the financial services business are insured by Ambac Assurance. As part of its refocused business strategy, Ambac decided to discontinue writing new business in its Financial Services segment. The interest rate swap and investment agreement businesses are being run off. In the process of doing so, we expect to execute hedging transactions to mitigate risks in the respective books of business to the extent that we are able to do so; the ratings and financial condition of Ambac Assurance, which acts as credit support provider with respect to these subsidiaries, will make execution of any such hedging transactions more difficult. Such hedging transactions may include execution of swaps or other derivative instruments for the purpose of re-hedging risks inherent in the investment agreement business and the interest rate and currency swap business.

As a holding company, Ambac is largely dependent on dividends from Ambac Assurance to pay dividends on its common stock, to pay principal and interest on its indebtedness and to pay its operating expenses. Ambac Assurance is unable to pay dividends to Ambac in 2009 without the consent of the Office of the Commissioner of Insurance of the State of Wisconsin. See Part I, Item 2 "Management's Discussion and Analysis-Liquidity and Capital Resources" of this Form 10-Q for further information.

Financial information concerning our business segments for each of 2009 and 2008 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, which are in Part I, Items 1, 2 and 3 of this Form 10-Q. Our Internet address is www.ambac.com. We make available free of charge, on or 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 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: 212-208-3333.

Critical Accounting Policies and Estimates

The discussion and analysis of our financial condition and results of operations are based upon our Consolidated Financial Statements, which have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP"). The preparation of these financial statements requires us to make estimates and judgments that affect the reported amount of assets and liabilities, revenues and expenses and related disclosure of contingent assets and liabilities at the date of our financial statements. Actual results may differ from these estimates under different assumptions or conditions.

Critical accounting policies are considered critical because they place significant importance on management to make difficult, complex or subjective estimates regarding matters that are inherently uncertain. Financial results could be materially different if alternative methodologies were used or if management modified its assumptions or estimates. Management has identified the accounting for loss and loss expenses of non-derivative financial guarantees, the valuation of financial instruments, including the determination of whether an impairment is other-than-temporary and the valuation allowance on deferred tax assets, as critical accounting policies. This discussion should be read in conjunction with the consolidated financial statements and notes thereon included elsewhere in this report, and in the 2008 Form 10-K filed with the SEC on March 16, 2009.

Financial Guarantee Insurance Losses and Loss Expenses. The loss reserve for financial guarantee insurance discussed herein relates only to Ambac's non-derivative insurance business. Losses and loss expenses are based upon estimates of the ultimate aggregate losses inherent in the non-derivative financial guarantee portfolio as of the reporting date. The evaluation process for determining the level of reserves is subject to certain estimates and judgments.

On May 23, 2008, the FASB issued SFAS 163, Accounting for Financial Guarantee Insurance Contracts, an interpretation of SFAS 60 Accounting and Reporting by Insurance Enterprises. The new standard clarifies how SFAS 60 applies to financial guarantee insurance contracts issued by insurance enterprises, including the recognition and measurement of claim liabilities (i.e., loss reserves). Ambac adopted the loss reserve provisions of SFAS 163 on January 1, 2009. SFAS 163 is required to be applied to inforce financial guarantee insurance contracts issued upon adoption as well as new financial guarantee contracts issued in the future.

Under SFAS 163 a loss reserve is recorded on the balance sheet for the excess of: (a) the present value of expected net cash outflows to be paid under an insurance contract, i.e. the expected loss, over (b) the unearned premium reserve ("UPR") for that contract. To the extent (a) is less than (b), no loss reserve is recorded. Changes to the loss reserve estimate in subsequent periods are recorded as a loss and loss expense on the income statement. Expected losses are based upon estimates of the ultimate aggregate losses inherent in the non-derivative financial guarantee portfolio as of the reporting date. The evaluation process for determining expected losses is subject to certain estimates and judgments based on our assumptions regarding the probability of default and expected severity of performing credits as well as our active surveillance of the insured book of business and observation of deterioration in the obligor's credit standing.

Ambac's loss reserves are based on management's on-going review of the non-derivative financial guarantee credit portfolio. Active surveillance of the insured portfolio enables Ambac's Surveillance Group to track credit migration of insured obligations from period to period and update internal credit ratings for

each transaction. Non-adversely classified credits are assigned a Class I or Survey List ("SL") rating while adversely classified credits are assigned a rating of Class IA through Class V. The criteria for an exposure to be assigned an adversely classified credit rating includes the deterioration of an issuer's financial condition, underperformance of the underlying collateral (for collateral dependent transactions such as mortgage-backed securitizations), poor performance by the servicer of the underlying collateral and other adverse economic events or trends. The servicer of the underlying collateral of an insured securitization transaction is a consideration in assessing credit quality because the servicer's performance can directly impact the performance of the related issue. For example, a servicer of a mortgage-backed securitization that does not remain current in its collection efforts could cause an increase in the delinquency and potential default of the underlying obligation.

The population of credits evaluated in Ambac's loss reserve process are: i) all adversely classified credits (Class IA through V) and ii) non-adversely classified credits (Class I and SL) which have been downgraded since the transaction's inception. One of two approaches are then utilized to estimate expected losses to ultimately determine if a loss reserve should be established for these credits. The first approach is statistical expected loss approach, which considers the likelihood of all possible outcomes. The "base case" statistical expected loss is the product of: (i) the net par outstanding on the credit; (ii) internally developed historical default information (taking into consideration internal ratings and average life of an obligation);
(iii) internally developed loss severities; and (iv) a discount factor. The loss severities and default information are based on rating agency information, are specific to each bond type and are established and approved by Ambac's Enterprise Risk Management Committee ("ERMC"), which is comprised of Ambac's senior risk management professionals and other senior management. For certain credit exposures, Ambac's additional monitoring and loss remediation efforts may provide information relevant to adjust this estimate of "base case" statistical expected losses. As such, ERMC-approved loss severities used in estimating the "base case" statistical expected losses may be adjusted based on the professional judgment of the surveillance analyst monitoring the credit with the approval of senior management. Analysts may accept the "base case" statistical expected loss as the best estimate of expected loss or assign multiple probability weighted severities to determine an adjusted statistical expected loss that better reflects a given transaction's potential severity.

For those credits meeting the above criteria that require further evaluation, one of two approaches are utilized to estimate expected losses to ultimately determine if a loss reserve should be established. The first approach is an adjusted statistical expected loss approach. This approach utilizes the same statistical loss calculation described above to derive a "base case" loss. For certain credit exposures, Ambac's additional monitoring and loss remediation efforts may provide information relevant to adjust this estimate of base case losses. As such, ERMC-approved loss severities used in estimating the base case statistical expected losses may be adjusted based on the professional judgment of the surveillance analyst monitoring the credit with the approval of senior management. Such adjustments consider the likelihood of all possible outcomes based on all relevant facts and circumstances that are available to our surveillance group. Analysts may accept the base case statistical expected loss as the best estimate of expected loss or assign multiple probability weighted severities to determine an adjusted statistical expected loss that better reflects a given transaction's potential severity. The second approach entails the use of more precise estimates of expected net cash outflows (future claim payments, net of potential recoveries, expected to be paid to the holder of the insured financial obligation). Ambac's surveillance group will consider the likelihood of all possible outcomes and develop cash flow scenarios. This approach can include the utilization of market accepted software tools to develop net claim payment estimates. We have utilized such tools for residential mortgage-backed exposures as well as certain other types of exposures. These tools, in conjunction with detailed data of the historical performance of the collateral pools, assist Ambac in the determination of certain assumptions, such as default and voluntary prepayment rates, which are needed in order to estimate expected future net claim payments. In this approach a probability-weighted expected loss estimate is

developed based on assigning probabilities to multiple net claim payment scenarios and applying an appropriate discount factor. A loss reserve is recorded for the excess, if any, of estimated expected losses (net cash outflows) using either of these two approaches, over UPR. For certain policies, estimated potential recoveries exceed estimated future claim payments because all or a portion of such recoveries relate to claims previously paid. The expected net cash inflows for these policies are recorded as a subrogation recoverable asset.

The discount factor applied to both of the above described approaches is based on a risk-free discount rate corresponding to the remaining expected weighted-average life of the exposure and the exposure currency. For example, U.S. dollar exposures are discounted using U.S. Treasury rates while exposures denominated in foreign currency are discounted using the appropriate risk-free rate for the respective currency. The discount factor is updated for the current risk-free rate each reporting period.

As the probability of default for an individual credit increases and/or the severity of loss given a default increases, our loss reserve for that insured obligation will also increase. Political, economic, credit or other unforeseen events could have an adverse impact on default probabilities and loss severities. Downgrades to the underlying rating of a credit, particularly those individual credits with a large net par balance, could have a significant impact on our reserves. Loss reserves for public finance or other non-collateral dependent transactions whose underlying financial obligations have already defaulted (that is a 100% probability of default) are only sensitive to severity assumptions. Loss reserves for collateral dependent transactions (such as mortgage-backed security transactions) for which a portion of the underlying collateral has already defaulted will be sensitive to both severity assumptions as well as probability of default of the underlying collateral.

Loss reserve volatility will be a direct result of the credit performance of our insured portfolio including the number, size, asset classes and quality of credits included in our loss reserves. The number and severity of credits included in our loss reserves depend to a large extent on transaction specific attributes, but will generally increase during periods of economic stress and decline during periods of economic stability. Historically, Ambac has not ceded large percentages of outstanding exposures to our reinsurers; therefore, reinsurance recoveries have not had a significant effect on loss reserve volatility. The current stressed credit environment has had an adverse impact on the financial strength of the reinsurers used by Ambac. Please refer to Item 3. "Quantitative and Qualitative Disclosures About Market Risk - Credit Risk" for further information and discussion.

The table below indicates the number of credits and net par outstanding for loss reserves on credits which have defaulted and all other credits at March 31, 2009:

  $ in millions       Number of credits    Net par outstanding     Net Loss Reserves
  Defaulted credits                  48   $              20,614   $             1,760
  All other credits                 148                  17,923                 1,134

  Totals                            196   $              38,537   $             2,894

Ambac has exposure to various bond types issued in the debt capital markets. Our experience has shown that, for the majority of bond types, we have not experienced claims and, therefore, the estimate of loss severity has remained constant. However, for certain bond types Ambac has loss experience that indicates that factors or events could have a material impact on the original estimate of loss severity. Historically, we have observed that, with respect to four bond types in particular, it is reasonably possible that a material change in actual loss severities and defaults could occur over time. In the future, including as a result of the current credit market crisis, our experience may differ with respect to the types of assets affected or the magnitude of the effect. The four bond types are residential mortgage-backed securities

("RMBS"); healthcare institutions; aircraft lease securitizations known as . . .