What Is a Workers Comp Experience Mod, and How Do You Lower It?

Your workers compensation experience modification factor, usually shortened to experience mod or e-mod, is a number that compares your company's actual claims history to what is expected for businesses of your size and industry. A mod of 1.0 is average. Your workers comp premium is multiplied by your mod, so a 1.25 mod raises the premium by 25 percent while a 0.85 mod cuts it by 15 percent.

For contractors and other companies that bid on work, the mod does double duty. It sets what you pay for workers comp, and it often decides whether you are allowed to bid at all.

What is an experience mod and who calculates it?

An experience mod is a rating factor calculated by an independent rating bureau, not by your insurance company. In most states that bureau is NCCI, the National Council on Compensation Insurance; a handful of states, including California, run their own bureaus. Your insurers are required to report your payroll and claims data to the bureau every year.

The bureau compares your actual losses to the expected losses for a business with your classification codes and payroll size. Better than expected produces a mod below 1.0, called a credit mod. Worse than expected produces a mod above 1.0, a debit mod.

Because the bureau does the math, the mod follows your business. Switching carriers does not reset it, and every insurer that quotes your account applies the same published factor.

How does the mod change what you pay?

The mod is a direct multiplier on your workers comp premium. Your base premium starts with payroll times the rate for each class code, and the mod is then applied to that number. A company with a 1.30 mod pays 30 percent more than an otherwise identical company at 1.0, and a company at 0.80 pays 20 percent less.

That multiplier applies every year, and each claim influences the mod for multiple years. So the real cost of a claim is not just the claim itself; it is the higher premium you pay on your entire payroll for the years that claim sits in your rating window.

Why does claim frequency hurt more than severity?

A string of small claims will usually raise your mod more than a single large claim of the same total cost. The rating formula splits each claim into a primary portion, counted at close to full weight, and an excess portion, which is heavily discounted. It also caps how much any single large loss can move the mod.

The logic is sound from an underwriting standpoint. One severe injury can be bad luck. Fifteen small injuries in three years point to something systemic, and frequency is one of the better predictors of future losses. Insurers price accordingly.

Two practical takeaways follow:

• Preventing routine injuries moves the mod most. A safety program aimed at your most common injury types does more for the mod than one aimed only at catastrophic risk.
• Hiding small claims is not the answer. Many states discount medical-only claims in the mod calculation, so a promptly reported claim that stays medical-only often has a modest effect. Failing to report claims, on the other hand, can create legal and coverage problems.

Which years of claims count toward your mod?

Your mod is typically built on three completed policy years, excluding the most recently completed one. The most recent year is left out because claims need time to develop before the data is reliable. That lag cuts both ways: this year's injuries will not show up in your mod immediately, and a bad year takes time to burn off once it enters the window.

Timing also matters inside the window. Claims are usually valued several months before your renewal, and open claims count at their reserved value as if fully paid. Two identical claims can affect your mod very differently depending on whether they are closed, or reserved conservatively, on the valuation date. That makes a pre-valuation claims review one of the most valuable meetings on your insurance calendar.

How does your mod affect construction prequalification and winning work?

On many construction projects, your mod is screened before your bid price is ever read. General contractors and project owners routinely ask for three years of experience mods on prequalification forms, and many treat a mod above 1.0 as a red flag. Some owners set hard cutoffs that keep contractors above the line off the bid list entirely, regardless of price or quality.

Third-party prequalification platforms have made this screening automatic and visible across every GC you register with. For a construction business, the practical result is that the mod is a revenue number, not just an insurance number. A high mod can cost far more in lost bid opportunities than it does in added premium, and a strong mod becomes a selling point in the interview.

Similar screening shows up in energy, industrial, and facility-services work, where site owners apply the same logic to anyone working on their property.

How can you lower your experience mod over time?

You lower a mod by reducing claim frequency, managing open claims actively, and correcting errors in the data. None of it is exotic, but it takes consistency across a few fronts:

• Run a real safety program. Target the injuries you actually have: strains, falls, cuts, whatever your loss runs show. Since frequency drives the formula, eliminating routine injuries is the single strongest lever.
• Use return-to-work aggressively. Modified or light duty gets injured employees back sooner, reduces lost-time costs, and often keeps claims in the cheaper medical-only category.
• Report claims fast. Claims reported quickly tend to close sooner and cost less. Slow reporting gives injuries time to complicate and invites disputes.
• Review open claims before the valuation date. Push adjusters to close claims that should be closed and to justify reserves that look inflated, since open reserves count against you as if paid.
• Audit the mod worksheet every year. Check payroll figures, class codes, and the claim list itself. Claims that belong to another employer, claims shown open after closing, and missed recovery credits all happen, and corrections can be filed.

None of these steps pays off overnight, because the rating window means today's improvements reach the mod on a delay. That is exactly why the companies with the best mods treat this as an ongoing discipline rather than a renewal-season scramble. It is also where structured risk advisory work earns its keep: mod projection, worksheet review, and claims strategy are repeatable processes, not one-time fixes.

Where a broker fits in

A good broker should pull your mod worksheet every year, reconcile it against your loss runs, project where your mod is heading, and run the pre-valuation claims review with you. If your mod is above 1.0, or you have never seen your worksheet, that is a solvable problem with a known playbook. Velora Risk Partners does this work with contractors and other mod-sensitive businesses; reach out if you want a second set of eyes on yours.

Frequently asked questions

What is a good experience mod?

Anything under 1.0 means your claims history is better than average for your industry and size, and it earns a premium credit. The lowest achievable mod varies by company because the formula limits how far a mod can move based on your size. For contractors, staying under 1.0 matters twice: it lowers premium, and it keeps you eligible on prequalification forms that often treat 1.0 as a cutoff.

Does my experience mod follow me if I switch insurance carriers?

Yes. The mod is calculated by a rating bureau, such as NCCI in most states, using claims data your insurers are required to report. Every carrier that quotes your account applies the same published mod, so changing insurance companies does not reset it. The only ways to improve a mod are to improve the underlying claims record or to correct errors in the data behind it.

How long does a claim stay on my experience mod?

A claim typically affects your mod for three rating years. It enters the calculation after a lag, because the experience window usually covers three completed policy years excluding the most recent one, and then it ages out. That means a bad claim year is not permanent, but it also means this year's injuries can still be raising your premium several years from now.

Can my experience mod be wrong?

Yes, and it is worth checking every year. Common errors include incorrect payroll figures, misassigned classification codes, claims that belong to a different employer, claims listed as open after they closed, and inflated reserves on open claims. Request your mod worksheet through your broker or the rating bureau and reconcile it against your own loss runs. Corrections can be filed, and a revised mod can change what you pay.

Do all businesses have an experience mod?

No. Experience rating applies only once your workers comp premium passes a threshold set by each state, so many small businesses are not experience rated at all. Below the threshold, you simply pay the manual rate for your class codes with no mod applied. As payroll grows, most companies cross the threshold, and from that point their claims history directly moves their premium up or down.