Chubb Ltd

Our Consolidated Financial Statements include amounts that, either by their nature or due to requirements of generally accepted accounting principles in the U.S. (U.S. GAAP), are determined using best estimates and assumptions. While we believe that the amounts included in our Consolidated Financial Statements reflect our best judgment, actual amounts could ultimately materially differ from those currently presented. We believe the items that require the most subjective and complex estimates are:

•unpaid loss and loss expense reserves, including long-tail asbestos and environmental (A&E) reserves and non-A&E casualty exposures;

•future policy benefits reserves;

•the valuation of value of business acquired (VOBA);

•the assessment of risk transfer for certain structured insurance and reinsurance contracts;

•reinsurance reco verable, including a valuation allowance for uncollectible reinsurance;

•the valuation of our investment portfolio and assessment of valuation allowance for expected credit losses;

•the valuation of deferred income taxes; and

•the assessment of goodwill for impairment.

We believe our accounting policies for these items are of critical importance to our Consolidated Financial Statements. The following discussion provides more information regarding the estimates and assumptions required to arrive at these amounts and should be read in conjunction with the sections entitled: Prior Period Development, Asbestos and Environmental (A&E), Reinsurance Recoverable on Ceded Reinsur ance, Investments, and Net Realized and Unrealized Gains (Losses).

Unpaid losses and loss expenses

As an insurance and reinsurance company, we are required by applicable laws and regulations and U.S. GAAP to establish loss and loss expense reserves for the estimated unpaid portion of the ultimate liability for losses and loss expenses under the terms of our policies and agreements with our insured and reinsured customers. At December 31, 2023, our gross unpaid loss and loss expense reserves were $80.1 billion and our net unpaid loss and loss expense reserves were $62.2 billion. With the exception of certain structured settlements, for which the timing and amount of future claim payments are reliably determinable, and certain reserves for unsettled claims, our loss reserves are not discounted for the time value of money. The net undiscounted reserves related to structured settlements and certain reserves for unsettled claims are immaterial.

The following table presents a roll-forward of our unpaid losses and loss expenses:

(1)Net of valuation allowance for uncollectible reinsurance.

The estimate of the liabilities includes provisions for claims that have been reported but are unpaid at the balance sheet date (case reserves) and for obligations on claims that have been incurred but not reported (IBNR) at the balance sheet date. IBNR may also include provisions to account for the possibility that reported claims may settle for amounts that differ from the established case reserves. Loss reserves also include an estimate of expenses associated with processing and settling unpaid claims (loss expenses). Our loss reserves comprise approximately 78 percent casualty-related business, which typically encompasses long-tail risks, and other risks where a high degree of judgment is required.

The process of establishing loss reserves for property and casualty claims can be complex and is subject to considerable uncertainty as it requires the use of informed estimates and judgments based on circumstances underlying the insured losses known at the date of accrual. For example, the reserves established for high excess casualty claims, asbestos and environmental claims, claims from major catastrophic events, or for our various product lines each require different assumptions and judgments to be made. The effects of recent heightened inflation create additional uncertainty, while climate change could, over time, add new uncertainties to the loss reserving process.

Necessary judgments are based on numerous factors and may be revised as additional experience and other data become available and are reviewed, as new or improved methods are developed, or as laws change. Hence, ultimate loss payments may differ from the estimate of the ultimate liabilities made at the balance sheet date. Changes to our previous estimates of prior period loss reserves impact the reported calendar year underwriting results adversely if our estimates increase or favorably if our estimates decrease. The potential for variation in loss reserve estimates is impacted by numerous factors. Reserve estimates for casualty lines are particularly uncertain given the lengthy reporting patterns and corresponding need for IBNR.

Case reserves for those claims reported by insureds or ceding companies to us prior to the balance sheet date and where we have sufficient information are determined by our claims personnel as appropriate based on the circumstances of the claim(s), standard claim handling practices, and professional judgment. Furthermore, for our Brandywine run-off operations and our assumed reinsurance operation, Global Reinsurance, we may adjust the case reserves as notified by the ceding company if the judgment of our respective claims department differs from that of the cedant.

With respect to IBNR reserves and those claims that have been incurred but not reported prior to the balance sheet date, there is, by definition, limited actual information to form the case reserve estimate and reliance is placed upon historical loss experience and actuarial methods to estimate the ultimate loss obligations and the corresponding amount of IBNR. IBNR reserve estimates are generally calculated by first projecting the ultimate amount of losses for a product line and subtracting paid losses and case reserves for reported claims. The judgments involved in projecting the ultimate losses may pertain to the use and interpretation of various standard actuarial reserving methods that place reliance on the extrapolation of actual historical data, loss development patterns, industry data, and other benchmarks as appropriate. The estimate of the required IBNR reserve also requires judgment by actuaries and management to reflect the impact of more contemporary and subjective factors, both qualitative and quantitative. Among some of these factors that might be considered are changes in business mix or volume, changes in ceded reinsurance structures, changes in claims handling practices, reported and projected loss trends, inflation, the legal environment, and the terms and conditions of the contracts sold to our insured parties.

Determining management's best estimate

Our recorded reserves represent management's best estimate of the provision for unpaid claims as of the balance sheet date, and establishing them involves a process that includes collaboration with various relevant parties in the company. For information on our reserving process, refer to Note 8 to the Consolidated Financial Statements.

Sensitivity to underlying assumptions

While we believe that our reserve for unpaid losses and loss expenses at December 31, 2023, is adequate, new information or emerging trends that differ from our assumptions may lead to future development of losses and loss expenses that is significantly greater or less than the recorded reserve, which could have a material effect on future operating results. As noted previously, our best estimate of required loss reserves for most portfolios is judgmentally selected for each origin year after considering the results from a number of reserving methods and is not a purely mechanical process. Therefore, it is difficult to convey, in a simple and quantitative manner, the impact that a change to a single assumption will have on our best estimate. In the examples below, we attempt to give an indication of the potential impact by isolating a single change for a specific reserving method that would be pertinent in establishing the best estimate for the product line described. We consider each of the following sensitivity analyses to represent a reasonably likely deviation in the underlying assumption.

North America Commercial P&C Insurance - Workers' Compensation

Given the long reporting and paid development patterns for workers' compensation business, the development factors used to project actual current losses to ultimate losses for our current exposure require considerable judgment that could be material to consolidated loss and loss expense reserves. Specifically, adjusting ground up ultimate losses by a one percentage point change in the tail factor (i.e., 1.04 changed to either 1.05 or 1.03) would cause a change of approximately $1.1 billion, either positive or negative, for the projected net loss and loss expense reserves. This represents an impact of about 10.7 percent relative to recorded net loss and loss expense reserves of approximately $10.2 billion.

North America Commercial P&C Insurance – Liability

As is the case for Workers’ Compensation above, given the long reporting and paid development patterns, the development factors used to project actual current losses to ultimate losses for our current exposure require considerable judgment that could be material to consolidated loss and loss expense reserves. Specifically, for our main U.S. Excess/Umbrella portfolios, a five percentage point change in the tail factor (e.g., 1.10 changed to either 1.15 or 1.05) would cause a change of approximately $0.7 billion, either positive or negative, for the projected net loss and loss expense reserves. This represents an impact of about 18 percent relative to recorded net loss and loss expense reserves of approximately $3.9 billion for these portfolios.

The reserve portfolio for our Chubb Bermuda operations contains exposure to predominantly high excess liability coverage on an occurrence-first-reported basis (typically with attachment points in excess of $325 million and gross limits of up to $150 million) and D&O and other professional liability coverage on a claims-made basis (typically with attachment points in excess of $100 million and gross limits of up to $75 million). Due to the layer of exposure covered, the expected frequency for this book is very low. As a result of the low frequency/high severity nature of the book, a small difference in the actual vs. expected claim frequency, either positive or negative, could result in a material change to the projected ultimate loss if such change in claim frequency was related to a policy where significant limits were deployed.

North America Personal P&C Insurance

Due to the relatively short-tailed nature of many of the coverages involved (e.g., homeowners property damage), most of the incurred losses in Personal Lines are resolved within a few years of occurrence. As shown in our loss triangle disclosure, the vast majority (almost 95 percent) of Personal Lines net ultimate losses and allocated loss adjustment expenses are typically paid within five years of the accident date and almost 80 percent within two years. Even though there are significant reserves associated with some liability exposures such as personal excess/umbrella liability, our incurred loss triangle also shows a roughly consistent pattern of only relatively minor movements in incurred estimates over time by accident year especially after twenty-four months of maturity. While the liability exposures are subject to additional uncertainties from more protracted resolution times, the main drivers of volatility in the Personal Lines business are relatively short-term in nature and relate to things like natural catastrophes, non-catastrophe weather events, man-made risks, and individual large loss volatility from other fortuitous claim events.

North America Agricultural Insurance

Approximately 69 percent of the reserves for this segment are from the crop related lines, which all have short payout patterns, with the majority of the liabilities expected to be resolved in the ensuing twelve months. Claim reserves for our Multiple Peril Crop Insurance (MPCI) product are set on a case-by-case basis and our aggregate exposure is subject to state level risk sharing formulae as well as third-party reinsurance. The majority of the development risk arises out of the accuracy of case reserve estimates and the time needed for final crop conditions to be assessed. We do not view our Agriculture reserves as substantially influenced by the general assumptions and risks underlying more typical P&C reserve estimates.

Overseas General Insurance

Certain long-tail lines, such as casualty and financial lines, are particularly susceptible to changes in loss trend and claim inflation. Heightened perceptions of tort and settlement awards around the world can increase the demand for these products as well as contributing to the uncertainty in the reserving estimates. Our reserving methods rely on loss development patterns estimated from historical data and while we attempt to adjust such factors for known changes in the current tort environment, it is possible that such factors may not entirely reflect all recent trends in tort environments. For example, when applying the reported loss development method, the lengthening of our selected loss development patterns by six months would increase reserve estimates on long-tail casualty and financial lines for accident years 2021 and prior by approximately $556 million. This represents an impact of 12 percent relative to recorded net loss and loss expense reserves of approximately $4.6 billion.

At December 31, 2023, net unpaid losses and loss expenses for the Global Reinsurance segment aggregated to $1.7 billion, consisting of $744 million of case reserves and $909 million of IBNR. In comparison, at December 31, 2022, net unpaid losses and loss expenses for the Global Reinsurance segment aggregated to $1.7 billion, consisting of $764 million of case reserves and $938 million of IBNR.

For our catastrophe business, we principally estimate unpaid losses and loss expenses on an event basis by considering various sources of information, including specific loss estimates reported by our cedants, ceding company and overall industry loss estimates reported by our brokers, and our internal data regarding reinsured exposures related to the geographical location of the event. Our internal data analysis enables us to establish catastrophe reserves for known events with more certainty at an earlier date than would be the case if we solely relied on reports from third parties to determine carried reserves.

For our casualty reinsurance business, we generally rely on ceding companies to report claims and then use that data as a key input to estimate unpaid losses and loss expenses. Due to the reliance on claims information reported by ceding companies, as well as other factors, the estimation of unpaid losses and loss expenses for assumed reinsurance includes certain risks and uncertainties that are unique relative to our direct insurance business. These include, but are not necessarily limited to, the following:

•The reported claims information could be inaccurate;

•Typically, a lag exists between the reporting of a loss event to a ceding company and its reporting to us as a reinsurance claim. The use of a broker to transmit financial information from a ceding company to us increases the reporting lag. Because most of our reinsurance business is produced by brokers, ceding companies generally first submit claim and other financial information to brokers, who then report the proportionate share of such information to each reinsurer of a particular treaty. The reporting lag generally results in a longer period of time between the date a claim is incurred and the date a claim is reported compared with direct insurance operations. Therefore, the risk of delayed recognition of loss reserve development is higher for assumed reinsurance than for direct insurance lines; and

•The historical claims data for a particular reinsurance contract can be limited relative to our insurance business in that there may be less historical information available. Further, for certain coverages or products, such as excess of loss contracts, there may be relatively few expected claims in a particular year so the actual number of claims may be susceptible to significant variability. In such cases, the actuary often relies on industry data from several recognized sources.

We mitigate the above risks in several ways. In addition to routine analytical reviews of ceding company reports to ensure reported claims information appears reasonable, we perform regular underwriting and claims audits of ceding companies to ensure reported claims information is accurate, complete, and timely. As appropriate, audit findings are used to adjust claims in the reserving process. We also use our knowledge of the historical development of losses from individual ceding companies to adjust the level of adequacy we believe exists in the reported ceded losses. If pricing a renewal contract, we compare data in the renewal submission to our financial data and investigate any discrepancies.

On occasion, there will be differences between our carried loss reserves and unearned premium reserves and the amount of loss reserves and unearned premium reserves reported by the ceding companies. This is due to the fact that we receive consistent and timely information from ceding companies only with respect to case reserves. For IBNR, we use historical experience and other statistical information, depending on the type of business, to estimate the ultimate loss. We estimate our unearned premium reserve by applying estimated earning patterns to net premiums written for each treaty based upon that treaty's coverage basis (i.e., risks attaching or losses occurring). At December 31, 2023, the case reserves, net of retrocessions, reported to us by our ceding companies approximated our recorded case reserves. Our policy is to post additional case reserves in addition to the amounts reported by our cedants when our evaluation of the ultimate value of a reported claim is different than the evaluation of that claim by our cedant.

Typically, there is inherent uncertainty around the length of paid and reported development patterns, especially for certain casualty lines such as excess workers' compensation or general liability, which may take decades to fully develop. This uncertainty is accentuated by the need to supplement client development patterns with industry development patterns due to the sometimes low statistical credibility of the data. The underlying source and selection of the final development patterns can thus have a significant impact on the selected ultimate net losses and loss expenses. For example, a 20 percent shortening or lengthening of the development patterns used for U.S. long-tail lines would cause the loss reserve estimate derived by the reported Bornhuetter-Ferguson method for these lines to change by approximately $185 million. This represents an impact of 23 percent relative to recorded net loss and loss expense reserves of approximately $815 million.

Within Corporate, we have exposure to certain liability insurance and reinsurance lines that have been in run-off, generally, since 1994. Unpaid losses and loss expenses relating to this run-off business reside within the Brandywine Division. Most of the remaining unpaid loss and loss expense reserves for the run-off business relate to A&E as well as molestation claims.

The A&E liabilities principally relate to claims arising from bodily-injury claims related to asbestos products and remediation costs associated with hazardous waste sites. The estimation of our A&E liabilities is particularly sensitive to future changes in the legal, social, and economic environment. We have not assumed any such future changes in setting the value of our A&E liabilities, which include provisions for both reported and IBNR claims.

There are many complex variables that we consider when estimating the reserves for our inventory of asbestos accounts and these variables may directly impact the predicted outcome. We believe the most significant variables relating to our asbestos liabilities include the current legal environment; specific settlements that may be used as precedents to settle future claims; assumptions regarding trends with respect to claim severity and the frequency of higher severity claims; assumptions regarding the ability to allocate liability among defendants (including bankruptcy trusts) and other insurers; the ability of a claimant to bring a claim in a state in which they have no residency or exposure; the ability of a policyholder to claim the right to unaggregated coverage; whether high-level excess policies have the potential to be accessed given the policyholder's claim trends and liability situation; payments to unimpaired claimants; and the potential liability of peripheral defendants. Based on the policies, the facts, the law, and a careful analysis of the impact that these factors will likely have on any given account, we estimate the potential liability for indemnity, policyholder defense costs, and coverage litigation expense.

The results in asbestos cases announced by other carriers or defendants may well have little or no relevance to us because coverage exposures are highly dependent upon the specific facts of individual coverage and resolution status of disputes among carriers, policyholders, and claimants.

Chubb's exposure to molestation claims principally arises out of liabilities acquired when it purchased CIGNA's P&C business in 1999 and Chubb Corp in 2016. The vast majority of the current liability relates to exposure from recently enacted "reviver" legislation in certain states that allow civil claims relating to molestation to be asserted against policyholders that would otherwise be barred by statutes of limitations.

For additional information refer to the “Asbestos and Environmental (A&E)” section and to Note 8 to the Consolidated Financial Statements.

Future policy benefits

Chubb issues contracts that are classified as long-duration, which generally cover accident and supplemental health (A&H) products; term, credit, and whole life products (both participating and non-participating); endowment products; and annuities. Accordingly, Chubb establishes a liability for future policy benefits (FPBL) which comprises the present value of estimated future policy benefits to be paid along with certain related expenses, less the present value of estimated future net premiums to be collected. For traditional and limited-payment life insurance contracts, the FPBL is established using a net premium valuation methodology, such that expected policyholder benefit payments are accrued in proportion to premium revenue recognized. Under the net premium methodology, a net premium ratio (NPR) is calculated which requires assumptions on the future cash flow impact of numerous factors including mortality, morbidity, persistency, policyholder behavior, discount rates, and unpaid loss adjustment expenses. We have elected to use unpaid loss adjustment expense assumptions that are locked in at contract inception and are not subsequently reviewed or updated. Except for these expenses, assumptions are regularly reviewed.

The following sections discuss the determination of assumptions that management believes to be critical accounting estimates, which depend on the application of significant, subjective, and complex judgments.

Determining management’s best estimates

For traditional and limited-payment long-duration contracts, actuarial assumptions on mortality, morbidity, persistency, and policyholder behavior represent management’s long-term best estimates. These best estimate assumptions are generally based on our experience, industry experience, or other factors if there is not sufficient credibility. In establishing best estimate assumptions, we take into consideration the prospective impact of experience deterioration, product changes, distribution changes, and other relevant environmental changes which could result in differences from historically observed experience. Generally, we do not expect trends to change significantly in the short term and, to the extent trends may change, we expect the change to be gradual over the long term. Best estimate assumptions are reviewed and updated at least annually, and may be updated in interim periods if we observe a material change indicative of a long-term trend. Changes to best estimate assumptions impact expected future cash flows and result in a remeasurement of the FPBL. The FPBL is also remeasured to account for differences between expected and actual experience on mortality, morbidity, and persistency. All such remeasurements are reflected in Policy benefits in the Consolidated statements of operations in the period in which best estimate assumptions were updated.

The discount rates used to calculate the net premium ratio are locked in at policy inception, and serve as the basis to recognize interest expense for the life of the policy. Discount rates used to measure the carrying value of the FPBL are updated quarterly, and the differences between the liability balances calculated using the locked-in discount rates and the updated discount rates are recognized in Other comprehensive income (OCI). The discount rate methodology is designed to prioritize observable inputs based on market data available in the local debt markets where the respective policies were issued in the currency in which the policies are denominated. For the discount rates applicable to tenors for which the single-A debt market is not liquid or there is little or no observable market data, we use various estimation techniques, which include, but are not limited to: (i) for tenors where there is less observable market data and/or the observable market data is available for similar instruments, estimating tenor-specific single-A credit spreads and applying them to risk-free government rates; (ii) for tenors where there is very limited or no observable single-A or similar market data, interpolation and extrapolation techniques.

Deferred profit liabilities

Reserves for limited-payment contracts, under which benefits extend beyond the period of premium collection, also include a deferred profit liability (DPL) that represents gross premiums received in excess of expected net premiums. The amortization of DPL is included in Policy benefits on the Consolidated statements of operations, and is in relation to either the discounted amount of insurance in force for life insurance, or expected benefit payments for annuity contracts. The DPL is subject to the same best estimate assumptions used to determine future policy benefits reserves, however, there is no remeasurement of the DPL using then-current discount rates.

Sensitivities to underlying assumptions

At December 31, 2023, our liability for future policy benefits was $13.9 billion. While we believe that our future policy benefits reserves are appropriate at December 31, 2023, new information or emerging trends that impact best estimate assumptions may have a material effect on the FPBL and future operating results.

In the table below, we give an indication of the potential impact on operating results from a hypothetical change in a single assumption; we do not consider a simultaneous change in a combination of assumptions. Additionally, the table assumes a parallel global shift in best estimate assumptions; however, these may be non-parallel in practice. While we consider each of the following assumption changes to represent a reasonably likely deviation, actual development may be materially different. Further, changes in best estimate assumptions could result in impacts to the Consolidated Financial Statements that are in excess of the amounts illustrated.

The following table shows the increase or (decrease) of the FPBL as a result of changes in various best estimate assumptions:

Valuation of value of business acquired (VOBA) and amortization of VOBA

As part of the acquisition of businesses that sell long-duration contracts, such as life products, we established an intangible asset related to VOBA, which represents the estimated fair value of the future profits of the in-force long duration contracts. The valuation of VOBA at the time of acquisition is derived from similar assumptions to those used to establish the associated future policy benefits reserves, including mortality, morbidity, persistency, investment yields, expenses, and the discount rate. The most significant input in this calculation is the discount rate used to arrive at the present value of the net cash flows. We amortize the VOBA as a component of Policy acquisition costs in the Consolidated statements of operations in relation to the profit emergence of the underlying contracts, which is generally in proportion to premium revenue recognized based upon the same assumptions used at the time of the acquisition.

At least annually, a review is performed of the recoverability of the VOBA asset using a premium deficiency test to ensure that the unamortized portion does not exceed the expected recoverable amounts. If it is determined that the premium margins or gross profits are less than the unamortized balance, then the asset will be adjusted downward with the adjustment recorded as an expense in the current period. Unrecoverable costs are expensed in the period identified.

Risk transfer

In the ordinary course of business, we both purchase (or cede) and sell (or assume) reinsurance protection. We discontinued the purchase of all finite risk reinsurance contracts, as a matter of policy, in 2002. For both ceded and assumed reinsurance, risk transfer requirements must be met in order to use reinsurance accounting, principally resulting in the recognition of cash flows under the contract as premiums and losses. If risk transfer requirements are not met, a contract is to be accounted for as a deposit, typically resulting in the recognition of cash flows under the contract through a deposit asset or liability and not as revenue or expense. To meet risk transfer requirements, a reinsurance contract must include both insurance risk, consisting of underwriting and timing risk, and a reasonable possibility of a significant loss for the assuming entity. We also apply similar risk transfer requirements to determine whether certain commercial insurance contracts should be accounted for as insurance or a deposit. Contracts that include fixed premium (i.e., premium not subject to adjustment based on loss experience under the contract) for fixed coverage generally transfer risk and do not require judgment.

Reinsurance and insurance contracts that include both significant risk sharing provisions, such as adjustments to premiums or loss coverage based on loss experience, and relatively low policy limits, as evidenced by a high proportion of maximum premium assessments to loss limits, can require considerable judgment to determine whether or not risk transfer requirements are met. For such contracts, often referred to as finite or structured products, we require that risk transfer be specifically assessed for each contract by developing expected cash flow analyses at contract inception. To support risk transfer, the cash flow analyses must demonstrate that a significant loss is reasonably possible. We use various tests to accomplish this, one of which is the ratio of the net present value of losses and commissions divided by the net present value of premiums equals or exceeds 110 percent with at least a 10 percent probability. For purposes of cash flow analyses, we generally use a risk-free rate of return consistent with the expected average duration of loss payments. In addition, to support insurance risk, we must prove the reinsurer's risk of loss varies with that of the reinsured and/or support various scenarios under which the assuming entity can recognize a significant loss.

To ensure risk transfer requirements are routinely assessed, qualitative and quantitative risk transfer analyses and memoranda supporting risk transfer are developed by underwriters for all structured products. We have established protocols for all products that include criteria triggering a risk transfer review of the contract prior to binding. If any criterion is triggered, a contract must be reviewed by a committee established by each of our segments with reporting oversight, including peer review, from our global Structured Transaction Review Committee.

With respect to ceded reinsurance, we entered into a few multi-year excess of loss retrospectively-rated contracts, principally in 2002. These contracts primarily provided severity protection for specific product divisions. Because traditional one-year reinsurance coverage had become relatively costly, these contracts were generally entered into in order to secure a more cost-effective reinsurance program. All of these contracts transferred risk and were accounted for as reinsurance. In addition, we maintain a few aggregate excess of loss reinsurance contracts that were principally entered into prior to 2003, such as the National Indemnity Company (NICO) contracts referred to in the section entitled, “Asbestos and Environmental (A&E)”. We have not purchased any other retroactive ceded reinsurance contracts since 1999.

With respect to assumed reinsurance and insurance contracts, products giving rise to judgments regarding risk transfer were primarily sold by our financial solutions business. Although we have significantly curtailed writing financial solutions business, several contracts remain in-force and principally include multi-year retrospectively-rated contracts and loss portfolio transfers. Because transfer of insurance risk is generally a primary client motivation for purchasing these products, relatively few insurance and reinsurance contracts have historically been written for which we concluded that risk transfer criteria had not been met. For certain insurance contracts that have been reported as deposits, the insured desired to self-insure a risk but was required, legally or otherwise, to purchase insurance so that claimants would be protected by a licensed insurance company in the event of non-payment from the insured.

Reinsurance recoverable

Reinsurance recoverable includes balances due to us from reinsurance companies for paid and unpaid losses and loss expenses and is presented net of a valuation allowance for uncollectible reinsurance. The valuation allowance for uncollectible reinsurance is determined based upon a review of the financial condition of the reinsurers and other factors. Ceded reinsurance contracts do not relieve our primary obligation to our policyholders. Consequently, an exposure exists with respect to reinsurance recoverable to the extent that any reinsurer is unable or unwilling to meet its obligations or disputes the liabilities assumed under the reinsurance contracts. We determine the reinsurance recoverable on unpaid losses and loss expenses using actuarial estimates as well as a determination of our ability to cede unpaid losses and loss expenses under existing reinsurance contracts.

The recognition of a reinsurance recoverable asset requires two key judgments. The first judgment involves our estimation based on the amount of gross reserves and the percentage of that amount which may be ceded to reinsurers. Ceded IBNR, which is a major component of the reinsurance recoverable on unpaid losses and loss expenses, is generally developed as part of our loss reserving process and, consequently, its estimation is subject to similar risks and uncertainties as the estimation of gross IBNR (refer to “Critical Accounting Estimates – Unpaid losses and loss expenses”). The second judgment involves our estimate of the amount of the reinsurance recoverable balance that we may ultimately be unable to recover from reinsurers due to insolvency, contractual dispute, or for other reasons. Estimated uncollectible amounts are reflected in a valuation allowance that reduces the reinsurance recoverable asset and, in turn, shareholders' equity. Changes in the valuation allowance for uncollectible reinsurance are reflected in net income.

Although the obligation of individual reinsurers to pay their reinsurance obligations is based on specific contract provisions, the collectability of such amounts requires estimation by management. The majority of the recoverable balance will not be due for collection until sometime in the future, and the duration of our recoverables may be longer than the duration of our direct exposures. Over this period of time, economic conditions and operational performance of a particular reinsurer may impact their ability to meet these obligations and while they may continue to acknowledge their contractual obligation to do so, they may not have the financial resources or willingness to fully meet their obligation to us.

To estimate the valuation allowance for uncollectible reinsurance, the reinsurance recoverable must first be determined for each reinsurer. This determination is based on a process rather than an estimate, although an element of judgment must be applied. As part of the process, ceded IBNR is allocated to reinsurance contracts because ceded IBNR is not generally calculated on a contract by contract basis. The allocations are generally based on premiums ceded under reinsurance contracts, adjusted for actual loss experience and historical relationships between gross and ceded losses. If actual premium and loss experience vary materially from historical experience, the allocation of reinsurance recoverable by reinsurer will be reviewed and may change. While such change is unlikely to result in a large percentage change in the valuation allowance for uncollectible reinsurance, it could, nevertheless, have a material effect on our net income in the period recorded.

Generally, we use a default analysis to estimate uncollectible reinsurance. The primary components of the default analysis are reinsurance recoverable balances by reinsurer, net of collateral, and forward looking default factors used to estimate the probability that the reinsurer may be unable to meet its future obligations in full. The definition of collateral for this purpose requires some judgment and is generally limited to assets held in a Chubb-only beneficiary trust, letters of credit, and liabilities held by us with the same legal entity for which we believe there is a right of offset. We do not currently include multi-beneficiary trusts. However, we have several reinsurers that have established multi-beneficiary trusts for which certain of our companies are beneficiaries. The determination of the default factor is principally based on the financial strength rating of the reinsurer and a corresponding default factor applicable to the financial strength rating. Default factors require considerable judgment and are determined using the current financial strength rating, or rating equivalent, of each reinsurer as well as other key considerations and assumptions. Significant considerations and assumptions include, but are not necessarily limited to, the following:

•For reinsurers that maintain a financial strength rating from a major rating agency, and for which recoverable balances are considered representative of the larger population (i.e., default probabilities are consistent with similarly rated reinsurers and payment durations conform to averages), the judgment exercised by management to determine the valuation allowance for uncollectible reinsurance of each reinsurer is typically limited because the financial rating is based on a published source and the default factor we apply is based on a historical default factor of a major rating agency applicable to the particular rating class. Default factors applied for financial ratings of AAA, AA, A, BBB, BB, B, and CCC, are 0.8 percent, 1.2 percent, 1.7 percent, 4.9 percent, 19.6 percent, 34.0 percent, and 62.2 percent, respectively. Because our model is predicated on the historical default factors of a major rating agency, we do not generally consider alternative factors. However, when a recoverable is expected to be paid in a brief period of time by a highly-rated reinsurer, such as certain property catastrophe claims, a default factor may not be applied;

•For balances recoverable from reinsurers that are both unrated by a major rating agency and for which management is unable to determine a credible rating equivalent based on a parent or affiliated company, we may determine a rating equivalent based on our analysis of the reinsurer that considers an assessment of the creditworthiness of the particular entity, industry benchmarks, or other factors as considered appropriate. We then apply the applicable default factor for that rating class. For balances recoverable from unrated reinsurers for which our ceded reserve is below a certain threshold, we generally apply a default factor of 34.0 percent;

•For balances recoverable from reinsurers that are either insolvent or under regulatory supervision, we establish a default factor and resulting valuation allowance for uncollectible reinsurance based on specific facts and circumstances surrounding each company. Upon initial notification of an insolvency, we generally recognize expense for a substantial portion of all balances outstanding, net of collateral, through a combination of write-offs of recoverable balances and increases to the valuation allowance for uncollectible reinsurance. When regulatory action is taken on a reinsurer, we generally recognize a default factor by estimating an expected recovery on all balances outstanding, net of collateral. When sufficient credible information becomes available, we adjust the valuation allowance for uncollectible reinsurance by establishing a default factor pursuant to information received; and

•For captives and other recoverables, management determines the valuation allowance for uncollectible reinsurance based on the specific facts and circumstances.

The following table summarizes reinsurance recoverables and the valuation allowance for uncollectible reinsurance for each type of recoverable balance at December 31, 2023:

(1) The valuation allowance for uncollectible reinsurance is based on a default analysis applied to gross reinsurance recoverables, net of approximately $4.4 billion of collateral at December 31, 2023.

At December 31, 2023, the use of different assumptions within our approach could have a material effect on the valuation allowance for uncollectible reinsurance. To the extent the creditworthiness of our reinsurers was to deteriorate due to an adverse event affecting the reinsurance industry, such as a large number of major catastrophes, actual uncollectible amounts could be significantly greater than our valuation allowance for uncollectible reinsurance. Such an event could have a material adverse effect on our financial condition, results of operations, and our liquidity. Given the various considerations used to estimate our uncollectible valuation allowance, we cannot precisely quantify the effect a specific industry event may have on the valuation allowance for uncollectible reinsurance. However, based on the composition (particularly the average credit quality) of the reinsurance recoverable balance at December 31, 2023, we estimate that a ratings downgrade of one notch for all rated reinsurers (e.g., from A to A- or A- to BBB+) could increase our valuation allowance for uncollectible reinsurance by approximately $97 million or approximately 0.5 percent of the gross reinsurance recoverable balance, assuming no other changes relevant to the calculation. While a ratings downgrade would result in an increase in our valuation allowance for uncollectible reinsurance and a charge to earnings in that period, a downgrade in and of itself does not imply that we will be unable to collect all of the ceded reinsurance recoverable from the reinsurers in question. Refer to Note 5 to the Consolidated Financial Statements, under item 8, for additional information.

Fair value measurements

Accounting guidance defines fair value as the price to sell an asset or transfer a liability (an exit price) in an orderly transaction between market participants and establishes a three-level valuation hierarchy based on the reliability of the inputs. The fair value hierarchy gives the highest priority to quoted prices in active markets (Level 1 inputs) and the lowest priority to unobservable data (Level 3 inputs). Level 2 includes inputs, other than quoted prices within Level 1, that are observable for assets or liabilities either directly or indirectly. Refer to Note 4 and Note 17 to the Consolidated Financial Statements, under item 8, for information on our fair value measurements.

Assessment of investment portfolio credit losses

Each quarter, we evaluate expected credit losses (ECL) for fixed maturity securities classified as available-for-sale. Because our investment portfolio is the largest component of consolidated assets, ECL could be material to our financial condition and results of operations. Refer to Notes 1 f) and 3 to the Consolidated Financial Statements, under item 8, for more information.

Deferred income taxes

At December 31, 2023, the Consolidated balance sheet reflects a deferred tax asset of $1.74 billion and a deferred tax liability of $1.56 billion. Our deferred tax assets and liabilities primarily result from temporary differences between the amounts recorded in our Consolidated Financial Statements and the tax basis of our assets and liabilities. We determine deferred tax assets and liabilities separately for each tax-paying component (an individual entity or group of entities that is consolidated for tax purposes) in each tax jurisdiction. The realization of deferred tax assets depends upon the existence of sufficient taxable income within the carryback or carryforward periods under the tax law in the applicable tax jurisdiction. There may be changes in tax laws in a number of countries where we transact business that impact our deferred tax assets and liabilities. At each balance sheet date, management assesses the need to establish a valuation allowance that reduces deferred tax assets when it is more likely than not that all, or some portion, of the deferred tax assets will not be realized. The determination of the need for a valuation allowance is based on all available information including projections of future taxable income, principally derived from business plans and where appropriate available tax planning strategies. Projections of future taxable income incorporate assumptions of future business and operations that are apt to differ from actual experience. If our assumptions and estimates that resulted in our forecast of future taxable income prove to be incorrect, an additional valuation allowance could become necessary, which could have a material adverse effect on our financial condition, results of operations, and liquidity. At December 31, 2023, the valuation allowance of $716 million reflects management's assessment that it is more likely than not that a portion of the deferred tax assets will not be realized due to the inability of certain subsidiaries to generate sufficient taxable income.

Goodwill impairment assessment

Goodwill, which represents the excess of acquisition cost over the estimated fair value of net assets acquired, was $19.7 billion and $16.2 billion at December 31, 2023 and 2022, respectively. During 2023, our Goodwill balance increased, primarily reflecting the consolidation of Huatai Group, which added $3.4 billion. Goodwill is assigned to applicable reporting units of acquired entities at the time of acquisition. Our reporting units are the same as our reportable segments. For Goodwill balances by reporting units, refer to Note 7 to the Consolidated Financial Statements, under item 8. Goodwill is not amortized but is subject to a periodic evaluation for impairment at least annually, or earlier if there are any indications of possible impairment. Impairment is tested at the reporting unit level. The impairment evaluation first uses a qualitative assessment to determine whether it is more likely than not (i.e., more than a 50 percent probability) that the fair value of a reporting unit is greater than its carrying amount. If a reporting unit fails this qualitative assessment, a single quantitative analysis is used to measure and record the amount of the impairment. In assessing the fair value of a reporting unit, we make assumptions and estimates about the profitability attributable to our reporting units, including:

•short-term and long-term growth rates; and

•estimated cost of equity and changes in long-term risk-free interest rates.

If our assumptions and estimates made in assessing the fair value of acquired entities change, we could be required to write-down the carrying value of Goodwill which could be material to our results of operations in the period the charge is taken. Based on our impairment testing for 2023, we determined no impairment was required and none of our reporting units were at risk for impairment.