How to Read Loss Runs Behind Your Workers' Comp EMR

Updated September 15, 2026

Your agent sent over a PDF with a dozen columns and forty rows of claim numbers, dates, and dollar figures. Somewhere in there is the reason your mod went up, if you can figure out which row and which column actually matter.

What a loss run actually is

Loss runs are the report your workers’ compensation carrier keeps of every claim filed under your policy: a claim number, the date it happened, a short description of the injury, its status, and its current value. Your agent or carrier can pull a current set for you, and you generally want one covering the same three policy years used in your experience rating worksheet, since that’s the report you’ll be checking it against. Every carrier’s report looks a little different, but the columns that actually matter are the same across all of them.

The columns worth reading first

Claim status. Open or closed. This is the single most important column on the page, because an open claim is valued differently than a closed one in your mod, and a claim that’s genuinely finished but still marked open keeps counting against you at an inflated number until someone catches it.

Reserve. The carrier’s current estimate of what an open claim will ultimately cost, medical and indemnity combined, paid and unpaid together. For any claim still open, this is the number your rating actually uses, not the amount paid so far. A reserve that’s a round number and hasn’t moved in a long time is usually a sign nobody’s revisited the file recently.

Paid to date. What’s actually gone out the door on the claim so far. Useful for context, since a large gap between paid and reserve on a claim that sounds mostly resolved is worth a second look, but paid to date is not the figure your mod is built from while a claim is open.

Date of injury and date reported. These tell you which policy year a claim belongs to, which matters because your rating is built from three specific years, skipping the most recent one. A claim showing up under the wrong policy year is rare, but worth catching, since it changes which ratings the claim actually affects.

Claimant and injury description. Enough detail to tell whether two rows might actually be describing the same incident, entered twice under two different claim numbers, especially after a carrier switch.

What to actually do with it

Sort by status first and separate open from closed. Read every open claim’s reserve and ask yourself, based on what you actually know about that claim, whether the number still makes sense. A worker who returned to full duty months ago with a claim still reserved at its original estimate is the most common version of a stale reserve, and it’s also the easiest one to get corrected once someone flags it.

Then check the closed claims for anything that’s still showing an active reserve instead of a final paid amount, which usually means the claim was resolved in the carrier’s file but never formally closed out.

Comparing loss runs to your worksheet

The loss runs and the worksheet should tell the same story about the same claims. If a claim on your worksheet shows a value that doesn’t match what your loss runs say for that same claim number, one of the two documents is out of date, and it’s worth finding out which one before you assume the higher number is correct. This comparison is the actual mechanism behind most of the ten specific errors worth checking for: almost none of them are visible from the worksheet alone. You find them by putting the two documents side by side.

Getting a currently valued set

Ask for loss runs that are currently valued, meaning pulled as of a recent date, not an old snapshot from your last renewal. A stale set won’t reflect a claim that closed, or a reserve that got corrected, since your last request. If you’re not sure how current a set is, the report itself usually states the “as of” date somewhere near the top, and it’s worth checking before you rely on it.

If you’ve switched carriers recently

A carrier switch in the middle of your three-year window means your claims for that window can be split across two carriers’ systems, and a single loss run request to your current carrier won’t cover the years still sitting with the prior one. If your policy changed carriers within the last three years, ask your agent for loss runs from both, covering whichever years each carrier actually held the policy. A gap here is easy to miss, since a report that looks complete from your current carrier can simply be silent about years it never covered.

When the numbers don’t add up

If a reserve looks wrong, or a claim looks closed but isn’t marked that way, the direct move is asking your agent or carrier to confirm the claim’s actual current status and correct the file if it’s out of date. That single request, sent early, is worth more than waiting for the next renewal to catch it. A reserve that comes down or a claim that closes after the valuation date reaches the next rating and the ones after it, so the earlier you raise it, the more ratings still have a chance to reflect it. If the loss runs show a claim that isn’t yours, or the same claim twice, that’s a reporting error, and in NCCI states a correction from your carrier produces a revised mod.

Getting the rest of the check done

Reading your own loss runs catches the obvious problems. A full worksheet verification goes further: every claim, every reserve, every class code compared against your source documents, with exactly what to send your agent or carrier for anything that’s wrong. Start with the free EMR Cost & Bid Check calculator to see what a correction could be worth, or get on the waitlist for the full review. It’s a flat fee, no contingency, and the savings are yours.