# What Is a Loss Run? How to Read One (With Example)

Original article: https://decla.com/guides/read-insurance-loss-runs

Text version: https://decla.com/guides/read-insurance-loss-runs/llms.txt

Author: Isaiah Hall

Published: 2026-10-20

Last reviewed: 2026-10-20

## Section outline

- [Who uses a loss run, and how to get one](https://decla.com/guides/read-insurance-loss-runs#who-uses-loss-runs)
- [What each part of a loss run means](https://decla.com/guides/read-insurance-loss-runs#fields)
- [How to read one, step by step](https://decla.com/guides/read-insurance-loss-runs#how-to-read)
- [Worked example: a commercial auto loss run](https://decla.com/guides/read-insurance-loss-runs#example)
- [Calculating a loss ratio](https://decla.com/guides/read-insurance-loss-runs#loss-ratio)
- [Turning loss runs into a loss summary and narrative](https://decla.com/guides/read-insurance-loss-runs#loss-narrative)
- [Workers’ comp loss runs: look for injury patterns](https://decla.com/guides/read-insurance-loss-runs#workers-comp)
- [Mistakes that end up in submissions](https://decla.com/guides/read-insurance-loss-runs#mistakes)
- [Spend your time on the story, not the spreadsheet](https://decla.com/guides/read-insurance-loss-runs#decla)
- [Related pages](https://decla.com/guides/read-insurance-loss-runs#related)
- [Sources](https://decla.com/guides/read-insurance-loss-runs#sources)

A loss run is an insurance company’s report of the claims on a policy: each claim’s date, description and status, and how much has been paid and set aside for it, as of a specific date. It’s also called a loss run report, loss history or claims history. Underwriters use it to decide whether to insure a business and at what price, so you’ll usually need one for each of the last three to five years when you shop for or renew commercial insurance.

Reading one well takes a specific order. First check what the report covers: the insured, the policy periods and the valuation date. Then check how it counts money, especially what’s inside “incurred.” Only then read the claims, starting with the open ones, because those numbers can still change.

This guide explains each part of a loss run, walks through a sample, shows how to calculate a loss ratio and write a loss narrative, and covers workers’ comp loss runs. The last section shows the same work with Decla, which reads the reports, puts them on one basis and drafts the summary for your team to review.

## Who uses a loss run, and how to get one

Underwriters are the main readers. When a business applies for new coverage or renews, the underwriter reviews its loss runs to judge how often it has claims and how costly they are. Most want three to five years of history, valued recently; within 30 to 90 days is common.

Business owners and their agents use loss runs to shop coverage, prepare a renewal and spot claims worth explaining before an underwriter asks. The insured can always get its own loss runs from the carrier, and an agent can usually request them on the insured’s behalf. Several states require carriers to send them within a set number of days. Our guide to requesting loss runs covers how, with a request letter you can copy.

## What each part of a loss run means

Carriers format loss runs differently and use slightly different labels, but nearly all of them report these fields. When a report has a key or footnotes, read those first; they tell you how that carrier defines its numbers.

| Field | What it means | Watch for |
| --- | --- | --- |
| Insured and policy | Whose claims, on which policy and line | Make sure it matches what you requested |
| Policy period | The dates the report covers | A report can cover less than you asked for |
| Valuation date (also “as of” or evaluation date) | The date the figures were measured | Not the same as the date the report was printed. Underwriters often want it within 30 to 90 days |
| Date of loss and date reported | When the incident happened, and when the carrier learned of it | A long gap between the two can draw questions |
| Status | Open, closed or reopened | Open claims can still grow or shrink |
| Paid | What the carrier has paid so far | Often split into loss (indemnity) and expense |
| Reserve (or outstanding) | The adjuster’s estimate of what’s still to be paid | An estimate, not money spent. It changes as the claim develops |
| Incurred | Paid plus reserve, as of the valuation date | Check whether it includes expenses and whether recoveries are subtracted |
| Recoveries | Money recovered through subrogation or salvage | Some carriers net it out of incurred, some show it separately |

## How to read one, step by step

1. Check what the report covers

   Confirm the insured, policy numbers, lines and periods match what you asked for, the valuation date is recent enough, and every page is there. If something is off, stop here and fix the request before reading further.

2. Read the carrier’s definitions

   Find out whether incurred includes defense and adjusting expenses, and whether recoveries are netted out. Two carriers’ “incurred” figures can measure different things, so you can’t compare or add them until you know.

3. Start with the open claims

   Open claims, especially those with large reserves, are where the account’s loss picture can still change. Note each one’s date, cause and reserve; these are what an underwriter will ask about first.

4. Look for patterns, not just totals

   Count claims by cause and by year. Several small claims of the same kind, or a rising count, can say more about the account than one large loss. Note claims that closed without payment too; they still count toward frequency.

5. Summarize what the underwriter will ask

   Write a short summary per policy period: claim count, paid, reserve and incurred on the same basis, the open claims and what’s behind them, and anything the client has done since, like a new safety program. Get facts on open claims from the adjuster or client rather than guessing.

## Worked example: a commercial auto loss run

Here’s a simplified two-year auto loss run for Sample Logistics LLC. The carrier’s key says incurred is paid plus reserve, including adjusting expenses, with no recoveries.

Sample loss run: Sample Logistics LLC, commercial auto, March 2024 to March 2026, valued February 15, 2026

| Claim | Date of loss | Description | Status | Paid | Reserve | Incurred |
| --- | --- | --- | --- | --- | --- | --- |
| A-101 | Jun 2024 | Rear-end collision, property damage | Closed | $12,400 | $0 | $12,400 |
| A-102 | Nov 2024 | Backed into a loading dock | Closed | $3,100 | $0 | $3,100 |
| A-103 | Aug 2025 | Intersection collision, bodily injury | Open | $18,000 | $45,000 | $63,000 |
| A-104 | Dec 2025 | Cargo damage alleged by customer | Closed, no payment | $0 | $0 | $0 |
| A-105 | Jan 2026 | Windshield replacement | Closed | $850 | $0 | $850 |
| Total |  | 5 claims | 1 open | $34,350 | $45,000 | $79,350 |

Total incurred is $79,350, but $45,000 of it is a reserve on one open claim. That’s the adjuster’s estimate, not money paid, and it could rise or fall before the claim closes. An underwriter will ask about A-103 first: what happened, whether liability is disputed, and whether the reserve looks adequate. Get those answers from the client or the adjuster before the submission goes out.

The count matters too: five claims in two years. A-104 closed without payment, but it still counts toward frequency. Three of the five were collisions, including the backing incident at the loading dock. If the client has added driver training or backup cameras since, say so in the submission; it’s the context the numbers can’t give.

And the valuation date is February 15. If the submission goes out in May, this report may be too old for the market, and A-103’s reserve may have changed. Check before you send.

## Calculating a loss ratio

A loss ratio compares losses to premium: incurred losses divided by earned premium for the same period. If Sample Logistics paid $90,000 in auto premium over these two years, its loss ratio is $79,350 ÷ $90,000, or about 88%.

Treat that as a starting point, not a verdict. Carriers calculate loss ratios differently, for example with or without expenses, or on written rather than earned premium. With a large open reserve, the ratio can move a lot before the claim closes. When you quote a loss ratio, say what’s in it and as of when.

## Turning loss runs into a loss summary and narrative

For a submission or a client review, nobody wants five carrier reports. Underwriters and clients want one summary across all of them, and a short narrative that explains the numbers. A useful one covers:

- Every policy period and line, with claim count, paid, reserve and incurred on the same basis, and the valuation date for each
- Each large or open claim: what happened, where it stands, and why the reserve is what it is
- Patterns across years, like a recurring cause or a rising claim count
- What the client has changed since, like new training, equipment or procedures
- Any gaps: periods still missing, or figures that couldn’t be compared

## Workers’ comp loss runs: look for injury patterns

Workers’ comp loss runs usually add fields like the body part injured, the nature of the injury (a strain, laceration or fracture) and the cause (lifting, a slip or fall, being struck by an object). Group claims by those fields across several years. If most claims are lifting strains in one part of the operation, that’s where training, equipment or a change in how the job is done can help most. It’s also the breakdown a loss control consultant or the client’s safety lead will want to see.

Two cautions. Workers’ comp loss runs include medical details about employees, so share only what each reader needs and keep names out of anything that leaves the agency. And a claim pattern is a starting point for a conversation with the client, not a diagnosis of their workplace.

## Mistakes that end up in submissions

Most loss run errors aren’t arithmetic. They come from reading a number without its context:

- Treating reserves as money paid. A reserve is an estimate that can change.
- Adding up reports with different valuation dates, as if the figures were measured at the same time.
- Counting the same claim twice when it appears on an older and a newer report.
- Adding two carriers’ incurred figures without checking that both define incurred the same way.
- Treating a missing policy period as a year with no claims.
- Reading a blank field as zero. Blank means unknown until the carrier says otherwise.

## Spend your time on the story, not the spreadsheet

Reading one loss run takes minutes. Reading five years of them from three carriers, putting them on the same basis and writing the summary takes hours, and it’s the part most likely to get rushed before a deadline. Decla does that work, and your team reviews what it produces. Decla:

- Reads each loss run and pulls the claims into one summary, with the valuation date and basis noted for every figure
- Compiles loss runs from multiple carriers and years into a loss summary and narrative for the submission or client review
- Breaks workers’ comp claims down by injury type, body part and cause, so you can see where intervention would help most

- [Start a free trial](https://app.decla.com/start-trial) — Run your next loss run review through Decla.

## Related pages

- [How to request loss runs](https://decla.com/guides/request-loss-runs) — What to include, who can ask, and how to follow up until every period is covered.

## Sources

- [Milliman: A beginner’s guide to the casualty actuarial language](https://www.milliman.com/en/insight/a-beginners-guide-to-the-casualty-actuarial-language) — Definitions of paid losses, case reserves and incurred losses.