A claims reserve, also called a loss reserve or outstanding claims provision, is the amount an insurer records as a liability for claims that have already occurred but have not yet been fully paid. It includes case reserves for claims that have been reported, an estimate for claims that have happened but have not yet been reported (incurred but not reported, or IBNR), and usually a reserve for the cost of settling claims.
For most non-life insurers, the claims reserve is the largest item among the liabilities on the balance sheet. It is an estimate, prepared by claims staff and actuaries, and every change in it flows through the income statement. It is the insurance counterpart of a bank's loan loss provision, but it covers events that have already happened rather than credit losses expected in future, which banks measure as expected credit loss.
Claims reserve in plain terms
Imagine a shop that sold a thousand kettles last year with a two-year guarantee. Some customers have already sent kettles back and are waiting for refunds. Others have broken kettles at home but have not yet complained. A careful shopkeeper puts money aside for both groups, using past experience to guess how many more complaints are coming.
A claims reserve is that money set aside. The insurer knows about some claims and can estimate each one. It also knows, from years of records, that more claims from last year will trickle in, sometimes many years later. Setting the reserve too low makes the business look healthier than it is; setting it too high hides profit. Getting it right is one of the central jobs of an insurance actuary.
Components of the reserve
- Case reserves. Amounts set by claims handlers on each reported claim, based on the facts known so far.
- IBNR. An actuarial estimate for claims that have occurred but not yet been reported, plus further development on known claims whose case reserves are expected to prove too low.
- Loss adjustment expense reserve. The expected cost of investigating, defending and settling the claims, covered in loss adjustment expense.
- Reinsurance and recoveries. Reported gross, with expected amounts from reinsurers and from salvage and subrogation shown as assets or deductions, depending on the accounting rules.
How reserves are estimated
Actuaries arrange past claims in a loss development triangle, showing how each accident year's paid or reported losses have grown over time. The chain-ladder method uses the average growth from one year of development to the next to project each year to its final, or ultimate, cost:
- Reported losses to date are paid losses plus case reserves.
- is the cumulative development factor, the product of the year-to-year growth factors still to come.
Suppose an accident year has $60 million of reported losses after two years, and history shows such years grow by a further 25% before they close (a factor of 1.25). Ultimate losses are $75 million and the IBNR is $15 million. For recent years with little data, actuaries often use the Bornhuetter-Ferguson method, which blends the development pattern with an expected loss ratio, and they adjust for inflation, changes in claims handling and legal trends.
Accounting and regulation
Under IFRS 17, effective from 1 January 2023, incurred claims form the liability for incurred claims: the expected future cash flows, discounted for the time value of money using a discount rate that reflects the liability's characteristics, plus a risk adjustment for uncertainty. EU insurers under Solvency II hold a best estimate plus a risk margin in their technical provisions.
US statutory accounting, set out in the NAIC's SSAP No. 55, requires management's best estimate of unpaid claims and loss adjustment expenses, generally without discounting. Insurers report ten years of reserve development by line in Schedule P of the annual statement, and property and casualty insurers must file a statement of actuarial opinion on the adequacy of their reserves as part of their regulatory reporting. Like other accruals under accrual accounting, the reserve matches the cost of claims to the period in which the insured events occurred.
Reserve development and risks
When later information shows a reserve was too low, the insurer records adverse development, a charge against current earnings; when it was too high, favourable development releases profit. Long-tail lines such as liability and workers' compensation are hardest to reserve, because claims can surface decades after the policy year, as asbestos and environmental claims showed. Analysts watch reserve development closely because a run of releases can flatter earnings and a sudden strengthening often signals deeper problems.
Reserves also drive reinsurance: a stop-loss or long-dated treaty recovery may depend on how the cedent's reserves develop, and auditors and supervisors test reserve methods for bias. An independent auditor typically uses its own actuaries to review the estimate.