Why Report Dates Define a Useful View
A claim can have several relevant dates. The event that caused the loss may occur in one year, the insurer may first learn about it in another, and payment may occur in a third. A report-year view answers a specific question: when did the insurer first receive notice of each claim? This perspective can help describe the flow of newly reported claims and compare the claims first reported in different periods.
The grouping rule is simple, but the dates are easy to confuse. A claim reported in January for an event that occurred in December belongs to the January report period, not the event’s occurrence period. A later payment does not move it to a new report period either.
The precise recording convention matters. For example, a data system may use the date a notice is received rather than the date an employee enters it. For a report-year analysis, use the stipulated first-report date consistently. Subsequent claim updates, reopening, or additional documentation do not change that original date unless the analysis explicitly defines a different grouping rule.
Three Ways to Group the Same Claims
A claim can be assigned to different experience periods depending on which date is the basis for grouping. The three views below answer different questions; none is a substitute for the others.
| View | Grouping date | Question it answers |
|---|---|---|
| Occurrence-year experience | Date the loss event occurred | Which events occurred during this period? |
| Report-year experience | Date the claim was first reported | Which claims first came to the insurer’s attention during this period? |
| Payment-year experience | Date a claim payment was made | Which payments were made during this period? |
The views can produce different claim counts and dollar totals even when they use the same underlying claims. In particular, a payment-year total groups transactions by payment date, while a report-year total groups claims by first-report date. A claim may have multiple payments, so counting payments is not necessarily the same as counting claims.
Worked Example: A Claim Reported After the Occurrence
A hypothetical insurer reviews the following three claims. For this example, use calendar years and count each listed claim once. The occurrence date, first-report date, and payment date are assumed recorded accurately. No interest, mortality, or probability model is used; the records are deterministic.
| Claim | Occurrence date | First-report date | Payment date | Payment |
|---|---|---|---|---|
| A | December 28, 2024 | January 4, 2025 | March 10, 2025 | $4,800 |
| B | February 10, 2025 | February 12, 2025 | December 5, 2025 | $1,200 |
| C | November 20, 2024 | December 30, 2024 | January 15, 2025 | $700 |
Step 1: Count claims by occurrence year. Claims A and C occurred in 2024, so the 2024 occurrence-year count is \(2\). Claim B occurred in 2025, so the 2025 occurrence-year count is \(1\).
Step 2: Count claims by report year. Claim C was first reported in 2024. Claims A and B were first reported in 2025. Therefore, the report-year counts are \(1\) for 2024 and \(2\) for 2025.
Step 3: Count payments by payment year. Claim C’s payment and Claim A’s payment occurred in 2025, as did Claim B’s. Thus, three payments were made in 2025. Their total is \( \$700+\$4{,}800+\$1{,}200=\$6{,}700\).
Check. The three claims appear once each in the full set. Their counts are \(2+1=3\) by occurrence year, \(1+2=3\) by report year, and three payments occurred in 2025. The 2025 report-year claim count is \(2\), not \(3\).
Method and trap avoided. The report-year method assigns each claim using its first-report date. Putting Claim A into 2024 because its loss occurred in 2024 is the common error: its occurrence year is 2024, but its report year is 2025.
Assigning Claims at Period Boundaries
A report period needs both a start and an end. Define whether endpoints are included so every first-report date belongs to exactly one period. For consecutive calendar years, a convenient convention is to include January 1 through December 31 in each year. For a fiscal year, state its start and end explicitly; do not assume that “fiscal year 2025” has a universal meaning.
A report-year assignment is a partition of the claims in scope: each claim has one first-report date and is placed in the single period containing that date. This gives a direct reason for a useful count identity. If the periods do not overlap and cover the full range of first-report dates, adding the counts across periods recovers the total number of claims in scope.
Here, \(N_j\) is the number of claims in report period \(P_j\), \(R_k\) is the first-report date for claim \(k\), and \(I(R_k\in P_j)\) equals \(1\) when that date falls in \(P_j\) and \(0\) otherwise. Each claim contributes to one period’s count because its first-report date falls in one and only one period. For a set of periods that covers all \(n\) claims, the indicators sum to one for each claim, so \(\sum_j N_j=n\). The identity does not hold for a selected subset of years if claims outside those years are also in the total \(n\).
Worked Example: Applying a Fiscal-Year Report Cutoff
A hypothetical insurer defines its report year as April 1 through March 31, inclusive. It labels April 1, 2024, through March 31, 2025, as fiscal report year 2024–25, and April 1, 2025, through March 31, 2026, as fiscal report year 2025–26. Use the recorded first-report dates below. A later update does not replace the first-report date. No interest, mortality, or probability model is used.
| Claim | First-report date | Later update, if any |
|---|---|---|
| D | March 31, 2025 | April 8, 2025 |
| E | April 1, 2025 | None |
| F | April 2, 2025 | None |
| G | April 1, 2024 | None |
Step 1: Classify Claim D. Its first report is March 31, 2025, the final included day of fiscal year 2024–25. Its later update is not a new first report. Assign it to fiscal report year 2024–25.
Step 2: Classify Claim E. April 1, 2025, is the first day of fiscal report year 2025–26, so assign Claim E to that year.
Step 3: Classify Claim F. April 2, 2025, is also within fiscal report year 2025–26, so assign Claim F to that year.
Step 4: Classify Claim G. April 1, 2024, is the first day of fiscal report year 2024–25, so assign Claim G to that year.
The fiscal report-year counts are \(2\) for 2024–25 (Claims D and G) and \(2\) for 2025–26 (Claims E and F). Check: \(2+2=4\), the total number of listed claims.
Method and trap avoided. Apply the stated inclusive boundaries to the first-report date. Treating April 1, 2025, as part of the fiscal year that just ended would misclassify Claim E; the defined period starts that day.
Report-Year Counts and Amounts
A report-year summary may include counts, amounts, or both, but the basis of each quantity should be stated. A count of claims first reported during a year is not a count of payments made during that year. Similarly, an amount can be organized by report year if it is measured for the claims in that report-year cohort. One must say what amount is being summarized and when it is measured.
For example, a table might show the total amount paid to date on claims first reported in each year, evaluated at a specified valuation date. That is a report-year grouping of claims, with a payment measure attached to each claim. It is not the same as total cash paid during each report year. If a claim has multiple payments, all payments included in the to-date measure remain associated with that claim’s report-year cohort, even if the payments occurred in later years.
A report-year count observed at a particular valuation date also has a scope limitation: it counts claims reported by that date. Claims from events that have not yet been reported are not in that observed count. This tutorial’s grouping rule assigns claims once their first-report dates are known; it does not estimate claims that are not yet reported.
Worked Example: Separating a Claim Cohort From Cash Paid in a Year
A hypothetical insurer has complete records through December 31, 2026, for the four claims below. The listed payment amount is the total paid on that claim by that date. For this example, use calendar years and include the entire listed amount once per claim. There is no interest, mortality, or probability model; no future payments are assumed beyond the stated records.
| Claim | Occurrence year | First-report date | Payment date | Total paid by Dec. 31, 2026 |
|---|---|---|---|---|
| H | 2023 | December 20, 2024 | February 10, 2025 | $3,000 |
| J | 2025 | January 10, 2025 | December 20, 2025 | $5,000 |
| K | 2024 | November 30, 2025 | January 15, 2026 | $2,000 |
| L | 2025 | January 3, 2026 | March 10, 2026 | $4,000 |
Step 1: Find 2025 report-year claims. Claims J and K were first reported in 2025. Their report-year count is \(2\), and the total paid on those claims by the stated valuation date is \( \$5{,}000+\$2{,}000=\$7{,}000\).
Step 2: Find payments made during 2025. Claims H and J were paid in 2025. Total cash paid in that calendar year is \( \$3{,}000+\$5{,}000=\$8{,}000\).
Step 3: Compare the summaries. The 2025 report-year cohort has two claims and $7,000 paid by the end of 2026. The 2025 payment-year total is $8,000. These amounts differ because Claim H was reported in 2024 but paid in 2025, while Claim K was reported in 2025 but paid in 2026.
Check. Claims H, J, K, and L are assigned to report years 2024, 2025, 2025, and 2026, respectively. The 2025 payment-year sum uses only H and J; its two listed payments sum to $8,000.
Method and trap avoided. First form the report-year cohort using first-report dates, then sum the stated measure for claims in that cohort. The incorrect calculation \( \$3{,}000+\$5{,}000=\$8{,}000\) as “2025 report-year payments” uses payment dates and includes Claim H while omitting Claim K.
Common Misreadings
- Using occurrence date instead of first-report date. This produces an occurrence-year view, even if the result is labelled report-year experience.
- Using payment date to assign claims. This groups cash transactions by payment year, not claims by report year.
- Moving a claim when it is updated. An update after the period boundary does not change the claim’s original first-report date under the stated convention.
- Leaving fiscal-year boundaries unstated. Name the start and end dates, and handle the boundary dates consistently.
- Mixing claim counts with payment counts. One claim may generate multiple payments; specify whether the unit being counted is a claim or a transaction.
Check Your Understanding
For each problem, identify the grouping date before calculating. Treat all scenarios as hypothetical and use the stated period conventions.
- A claim occurred on December 29, 2025, was first reported on January 2, 2026, and was paid on March 1, 2026. What are its occurrence year, report year, and payment year? (Answer: occurrence year 2025; report year 2026; payment year 2026.)
- A report period is the calendar year 2025. Four claims have first-report dates of December 31, 2024; January 1, 2025; December 31, 2025; and January 1, 2026. How many belong to the 2025 report period? (Answer: 2 claims.)
- A hypothetical fiscal report year runs from July 1 through June 30, inclusive. Claims are first reported on June 30, 2025, July 1, 2025, and June 30, 2026. How many belong to fiscal report year 2025–26, defined as July 1, 2025, through June 30, 2026? (Answer: 2 claims.)
- Three claims have first-report dates in 2025 and total payments by the valuation date of $1,250, $2,300, and $450. One additional claim was first reported in 2024 and paid $900 during 2025. What is the total paid by the valuation date on the 2025 report-year cohort, and what is the 2025 payment-year total if all four listed amounts were paid during 2025? (Answer: 2025 report-year cohort total $4,000; 2025 payment-year total $4,900.)
- In a hypothetical data set, five claims have first-report dates in 2024 and seven have first-report dates in 2025. No claims outside those years are in scope. One 2024 claim is updated in January 2025 but retains its recorded first-report date. What is the total claim count, and how many claims are in each report year? (Answer: total 12 claims; 5 in report year 2024 and 7 in report year 2025.)