Every year, a few months before your workers’ compensation policy renews, your carrier or agent can produce a document called a loss run. It is a claim-by-claim history of your policy: what was reported, what was paid, what is still reserved, and what is closed. Most business owners glance at the total and move on. That is a missed opportunity, because the loss run is one of the few documents that directly shapes what you will pay next year and how underwriters see your business.
This article explains what a loss run contains, how to read it, what to look for, and how to use it to your advantage before renewal rather than after.
What a Loss Run Actually Is
A loss run is a report generated from the carrier’s claim system, typically covering three to five policy years. For each claim, it usually shows the date of injury, the date the claim was reported, the claimant’s name or an identifier, a short description of the injury, the claim status, and the dollar figures: amounts paid for medical, amounts paid for indemnity or lost wages, expenses, and the reserves the carrier has set aside for future costs.
The total incurred figure for each claim is paid plus reserved. That number, not just what has been paid so far, is what underwriters and the experience rating system use.
You are generally entitled to request loss runs from your current and prior carriers, and most states require carriers to provide them within a set number of days. If you are shopping the policy, new carriers will require them.
Open Claims and Reserves Deserve the Most Attention
The single most useful habit is to look at every open claim and ask whether the reserve makes sense. Reserves are the adjuster’s estimate of what the claim will ultimately cost. They are set early, often with limited information, and they are not always updated as the claim develops.
A claim for a minor strain that has had no medical activity in eight months but still carries a large reserve is worth a conversation. An employee who has returned to full duty but whose claim remains open with an indemnity reserve is worth a conversation. Reserves that are higher than the claim will actually cost inflate your incurred losses, which can inflate your experience modification and your premium.
Ask your agent to request a reserve review or a claim status update from the adjuster on any open claim that looks stale. Adjusters handle many files, and a polite inquiry often prompts a reserve reduction or a closure.
Patterns Tell a Story That Totals Do Not
Once you have looked at individual claims, step back and look for patterns. Are most injuries coming from one department, one shift, one supervisor, or one type of task? Are there repeated back strains from the same lifting job? Are there several slip injuries near the same entrance? A cluster of similar claims points at a fixable cause, and fixing it does more for your premium over time than any negotiation.
Also look at the lag between injury date and report date. Claims reported days or weeks after the injury tend to cost more, partly because early medical care is delayed and partly because late-reported claims are harder to manage. If your loss run shows consistent reporting lag, your internal reporting process needs attention.
Medical-Only Versus Indemnity Claims
Loss runs distinguish between claims that involved only medical treatment and claims that involved lost time and wage replacement. The distinction matters more than it looks. In most states, medical-only claims are discounted heavily in experience rating, while indemnity claims count in full. A claim that crosses from medical-only into lost time, even by a few days, can have an outsized effect on your mod.
This is one reason return-to-work programs matter so much. Getting an injured employee back on modified duty quickly can keep a claim in the medical-only category, which is better for the employee and better for your rating.
Check for Errors
Loss runs contain mistakes more often than owners expect. Claims coded to the wrong policy year. Claims that belong to a different company with a similar name. Claims that were closed but still show as open. Subrogation recoveries that were collected but never credited. Reserves that were reduced in the claim file but never flowed through to the report.
Compare the loss run against your own incident records. Every claim on the report should correspond to an incident you know about. If something does not match, raise it before the data is used for renewal or for your experience modification calculation, because correcting it afterward is much harder.
Timing: Why Months Before Renewal Matters
Experience modifications are typically calculated using loss data valued at a specific point, often about six months before the rating effective date. Claims that are still open at that valuation date are counted at their reserved value. If you can get claims closed or reserves reduced before that valuation, the improvement shows up in your mod. If you wait until renewal, the data has already been captured.
The practical takeaway is to pull loss runs at least four to five months before renewal, review open claims, and push for closures and reserve adjustments before the valuation date. Your agent can tell you when that date falls for your policy.
Using Loss Runs When You Shop
If you are marketing your policy to other carriers, loss runs are the first thing an underwriter will read. A clean loss run with a short narrative explaining any large claim and the corrective action you took is far more persuasive than the numbers alone. Underwriters are generally more comfortable with a business that had a bad claim and fixed the cause than with one that cannot explain its history.
Make It a Routine
Reading loss runs is not complicated, but it requires doing it on a schedule and knowing what to ask. An independent agent who specializes in workers’ compensation can pull the reports, flag stale reserves, request adjuster reviews, and help you build the case for a better renewal. Treating the loss run as a working document rather than a bill you receive once a year is one of the most practical ways a business owner can take control of workers’ comp costs.