A loss run is a report issued by a carrier listing the claims made against a policy over a given period, showing dates, descriptions, amounts paid, reserves and status. Most markets ask for three to five years, and the report is the primary evidence of how an account has actually performed.
Updated September 2026.
Why it matters
Loss runs drive pricing more than almost anything else in a submission, and they are frequently the thing holding one up. They arrive late, in inconsistent formats, sometimes as scans, and reserves on open claims move between the date of the report and the date of the quote. An underwriter reading a stale loss run is pricing a different account than the one in front of them.
What to check
- That the period covers what the market requires, usually three to five years
- Whether open claims carry reserves that have moved since issue
- That the report is valued recently enough for the market to accept
- Whether large losses have explanatory narrative attached
- That the named insured on the loss run matches the submission
Common mistake
Submitting a loss run valued months ago. Reserves on open claims move, and an underwriter reading a stale report is pricing a different account than the one in front of them.
Reading submission documents at volume is covered in the contract requirements guide.