Why Policy Period Assignment Matters
A claim can involve several dates: the date of the event, the date the claim is first reported, and the date a payment is made. These dates can fall in different policy terms. Policy period assignment determines which policy period receives the claim for experience analysis, based on the coverage terms and the applicable trigger—not simply whichever date is easiest to find in a data file.
For occurrence-based coverage, the relevant date is generally the date of the covered occurrence. For claims-made coverage, the policy may instead respond when a claim is first made and reported during the term, subject to conditions such as a retroactive date and reporting requirements. The actual contract wording controls. In either case, a later report or payment does not automatically move an occurrence-based claim to a later policy period.
The method here is aligned with the CAS Exam 5 (Basic Ratemaking and Estimated Claim Liabilities) syllabus. It assumes that a claim’s relevant dates, applicable policy, coverage type, and covered amount have been identified. Assignment is not itself a decision that a claim is covered or a determination of its ultimate amount.
Start With the Policy and the Coverage Trigger
Do not begin by sorting claims according to a single date field. First identify the insured, policy, coverage, and term that could apply. Then determine what event or reporting condition triggers that coverage. The same occurrence date can lead to different assignments under different policy forms.
Confirm the insured or covered item, coverage type, and policy term. A policy may not cover every insured, vehicle, location, or type of loss in a dataset.
For occurrence-based coverage, use the date of the covered occurrence, subject to the policy wording. For claims-made coverage, use the applicable claim-made and reporting conditions, including any retroactive-date requirement.
Compare the relevant date with the policy’s effective and expiration dates. Under the half-open interval convention, a date at the effective boundary belongs to that term; a date at its expiration boundary does not.
Assign a claim to a term only when its trigger and other stated coverage conditions are met. Record claims that fail those conditions as not assigned to that policy’s covered experience, rather than forcing them into the nearest period.
Adjacent terms can be written as \([e_1,x_1)\) and \([x_1,x_2)\). This convention gives the shared boundary \(x_1\) to the second term, not both terms. Actual policies may specify expiration times or other boundary details; use the contract’s exact effective and expiration provisions when available.
Occurrence-Based Coverage
Under occurrence-based coverage, the relevant event is generally the covered occurrence during the policy term. The claim can be reported or paid after the term ends and still be associated with the policy in force on the occurrence date, assuming the claim otherwise satisfies the coverage terms. This is why occurrence date and report or payment dates must not be treated as interchangeable.
Worked Example: Claims Reported and Paid After an Occurrence Term
A hypothetical insurer is reviewing occurrence-based liability coverage for an insured. Policy A runs from July 1, 2023, through June 30, 2024, with its term represented as \([2023\text{-}07\text{-}01,2024\text{-}07\text{-}01)\). Policy B runs from July 1, 2024, through June 30, 2025, represented as \([2024\text{-}07\text{-}01,2025\text{-}07\text{-}01)\). Assume all three claims below are covered, and use each stated amount as the claim amount for this assignment exercise.
| Claim | Occurrence date | Report date | Payment date | Amount |
|---|---|---|---|---|
| A | December 20, 2023 | August 3, 2024 | December 10, 2024 | $6,400 |
| B | June 30, 2024 | June 30, 2024 | July 18, 2025 | $2,700 |
| C | July 1, 2024 | July 12, 2025 | March 2, 2026 | $5,100 |
Step 1: Assign Claim A. Its occurrence date, December 20, 2023, is within Policy A’s interval \([2023\text{-}07\text{-}01,2024\text{-}07\text{-}01)\). Its later report and payment dates do not change the occurrence-based assignment. Assign $6,400 to Policy A.
Step 2: Assign Claim B. June 30, 2024, is also within Policy A’s interval: it is before the July 1, 2024 expiration boundary. Assign $2,700 to Policy A, even though payment occurs during the calendar dates of Policy B.
Step 3: Assign Claim C. July 1, 2024, is the effective date of Policy B and is included in \([2024\text{-}07\text{-}01,2025\text{-}07\text{-}01)\). Assign $5,100 to Policy B.
Step 4: Aggregate and check. Policy A receives two claims totaling \(6{,}400+2{,}700=\$9{,}100\). Policy B receives one claim totaling \(\$5{,}100\). The assigned amounts sum to \(\$9{,}100+\$5{,}100=\$14{,}200\), equal to the three claim amounts \(6{,}400+2{,}700+5{,}100=\$14{,}200\). The method is occurrence-date assignment; the common mistake avoided is moving a claim because its report or payment falls after renewal.
Claims-Made Coverage
A claims-made policy does not use the occurrence date alone to determine its policy-period assignment. In a simplified claims-made-and-reported arrangement, the claim must satisfy the policy’s definition of when it is first made and the requirement that it be reported within the term. A retroactive date may also restrict which earlier occurrences are eligible. Other policy conditions can affect the result, so this simplified rule should not replace the actual contract wording.
For the example below, assume “reported date” is the date the claim is first made and reported under the stated policy wording. Assume the claim meets all other requirements unless a retroactive-date failure is specified.
Worked Example: Claims-Made-and-Reported Terms at Renewal
A hypothetical professional services insured has two claims-made-and-reported policies. Policy M1 runs from January 1, 2024, through December 31, 2024, with interval \([2024\text{-}01\text{-}01,2025\text{-}01\text{-}01)\). Policy M2 runs from January 1, 2025, through December 31, 2025, with interval \([2025\text{-}01\text{-}01,2026\text{-}01\text{-}01)\). Both have a retroactive date of January 1, 2022. Three otherwise distinct claims have these details:
| Claim | Occurrence date | First made and reported | Amount |
|---|---|---|---|
| D | August 15, 2022 | December 31, 2024 | $18,000 |
| E | December 20, 2024 | January 1, 2025 | $11,000 |
| F | May 10, 2021 | December 20, 2024 | $7,000 |
Step 1: Test Claim D. Its first-made-and-reported date, December 31, 2024, is within M1’s term. Its occurrence date, August 15, 2022, is not before the January 1, 2022 retroactive date. Under the stated assumptions, assign $18,000 to M1.
Step 2: Test Claim E. January 1, 2025, is the effective date of M2 and is excluded from M1’s term but included in M2’s term. Its occurrence date is after the retroactive date. Assign $11,000 to M2. The fact that the occurrence happened during M1 does not override the claims-made-and-reported trigger in this example.
Step 3: Test Claim F. Its first-made-and-reported date is within M1, but its occurrence date, May 10, 2021, is before the retroactive date of January 1, 2022. It therefore fails the stated retroactive-date condition and is not assigned to M1 as a covered claim.
Step 4: Check the assigned totals. M1 receives $18,000, M2 receives $11,000, and Claim F contributes no covered amount to either policy under the stated facts. The assigned covered amount is \(18{,}000+11{,}000=\$29{,}000\). Adding Claim F’s $7,000 would produce $36,000, but that would incorrectly include a claim that fails the stated condition. The method is to apply the claims-made reporting term and retroactive date; the trap is assigning solely by occurrence date or overlooking the retroactive date.
Why the Boundary Convention Works
Suppose consecutive policy terms meet exactly: the first ends when the second begins. Represent them as \([e_1,x_1)\) and \([x_1,x_2)\). A trigger date before \(x_1\), but on or after \(e_1\), is in the first term; a trigger date equal to \(x_1\) is in the second. Thus the shared boundary has one assignment rather than two.
This is a bookkeeping convention consistent with contiguous terms when the dates and times are recorded precisely. It prevents double assignment at renewal and leaves no gap between adjacent terms. If a policy expires at a particular time rather than at the start of a date, the exact time matters; a date-only extract may not be enough to resolve the assignment.
Midterm Coverage Changes and Claim-Level Checks
The policy’s annual start and end dates are not the only dates to check. An endorsement may add a vehicle, location, insured, or coverage part partway through a term. A claim can fall within the overall policy term but still fail to match the effective dates or scope of the relevant coverage. Assignment should therefore be based on the policy and coverage that actually apply to the claim, not just the named insured’s renewal calendar.
Worked Example: A Vehicle Added During the Policy Term
A hypothetical commercial auto policy runs from April 1, 2024, through March 31, 2025. Vehicle V3 is added by endorsement effective November 15, 2024. Assume the endorsement adds V3 to the relevant coverage from that effective date onward, and assume all other coverage conditions are satisfied. Two covered-loss amounts are proposed for V3:
| Claim | Occurrence date | Report date | Payment date | Amount |
|---|---|---|---|---|
| G | November 14, 2024 | November 20, 2024 | February 1, 2025 | $1,200 |
| H | November 15, 2024 | November 16, 2024 | April 4, 2025 | $2,000 |
Step 1: Check the overall policy term. Both occurrence dates are within the policy term \([2024\text{-}04\text{-}01,2025\text{-}04\text{-}01)\).
Step 2: Check when V3’s coverage begins. Claim G occurred November 14, one day before the endorsement’s November 15 effective date. Under the stated facts, it is not eligible under this policy’s V3 coverage and is not assigned as a covered amount to this policy. Claim H occurred on November 15, the included effective date, so it satisfies the stated timing condition.
Step 3: Assign and check the amount. Assign Claim H’s $2,000 to the policy period. The report and payment dates do not move it to another term. The assigned covered amount is $2,000, not \(1{,}200+2{,}000=\$3{,}200\), because Claim G fails the stated coverage-effective-date condition. The method is to check both the policy term and the item-specific coverage dates; the common mistake avoided is treating the full annual term as proof that every item was covered throughout it.
Common Mistakes and Practical Controls
- Using the wrong date field. For occurrence-based coverage, a later report or payment date does not replace the occurrence date. For claims-made coverage, do not automatically use the occurrence date as the period trigger.
- Putting a boundary date in both terms. With adjacent intervals \([e_1,x_1)\) and \([x_1,x_2)\), a trigger exactly at \(x_1\) belongs to the second term, not the first.
- Ignoring eligibility conditions. A claims-made report within the term may still fail a retroactive-date requirement. An occurrence during an annual term may also fall outside the effective coverage for a particular item or coverage part.
- Equating assignment with coverage determination. A date match is not enough to prove coverage. The policy’s definitions, exclusions, limits, reporting terms, and endorsements may affect whether a claim is eligible.
- Relying on incomplete or rounded dates. If the policy specifies effective or expiration times, use those precise values. Date-only records can misclassify boundary events when the contract’s time convention is not reflected in the data.
A reliable assignment record preserves the claim identifier, policy identifier, coverage part, relevant trigger date, policy effective and expiration dates, and the reason for the assignment or exclusion. These fields make it possible to review whether an apparent difference in totals is caused by the trigger, a boundary, an endorsement, or a missing coverage condition.
Check Your Understanding
For each question, assume the policy wording and coverage conditions stated are complete. Apply the trigger and boundary conventions carefully.
- An occurrence-based policy runs from April 1, 2025, through March 31, 2026. A covered event occurs March 31, 2026, is reported April 2, 2026, and has an assigned claim amount of $2,450. To which policy period does it belong, and what amount is assigned? (Answer: The term \([2025\text{-}04\text{-}01,2026\text{-}04\text{-}01)\); $2,450.)
- Two consecutive occurrence-based terms are \([2024\text{-}01\text{-}01,2025\text{-}01\text{-}01)\) and \([2025\text{-}01\text{-}01,2026\text{-}01\text{-}01)\). Covered events occur December 31, 2024, for $6,000 and January 1, 2025, for $9,000. Give the assigned amount in each term. (Answer: First term, $6,000; second term, $9,000.)
- A claims-made-and-reported term is \([2025\text{-}07\text{-}01,2026\text{-}07\text{-}01)\), with retroactive date July 1, 2023. Claim A arises from a June 2024 event and is first made and reported July 1, 2025. Claim B arises from a May 2022 event and is first made and reported July 1, 2025. Which claim satisfies the stated timing conditions? (Answer: Claim A only; Claim B is before the retroactive date.)
- A vehicle is added to a policy by endorsement effective November 15, 2024. It is involved in two otherwise covered occurrences, one on November 14 for $1,200 and one on November 15 for $2,000. Both occur during the overall annual policy term. What amount is assigned as covered loss for this vehicle under the stated endorsement? (Answer: $2,000; the November 14 occurrence precedes the vehicle’s coverage effective date.)
- An occurrence-based policy ends at the start of January 1, 2025, and its renewal begins at that same instant. A covered occurrence happens on January 1, 2025, at 12:00 a.m. and is reported a week later. To which term does it belong under the half-open interval convention? (Answer: The renewal term, because January 1, 2025, is its included effective boundary and the prior term’s excluded expiration boundary.)