Your experience modification rate — also called your e-mod, EMR, or mod factor — is the single biggest variable in your workers’ compensation premium. It’s a multiplier applied directly to your base premium: a mod of 1.20 means you’re paying 20% more than the industry average, while a mod of 0.85 means you’re paying 15% less.
Here’s the problem: experience modification rates frequently contain errors. Premium recovery specialists consistently find discrepancies in a majority of the mod worksheets they review — and those errors nearly always result in employers paying more than they should.
If your experience mod seems too high, it might not just feel wrong — it might actually be wrong.
What Is the Experience Modification Rate?
Your experience mod is essentially a safety scorecard. It compares your company’s actual claims history against what’s expected for businesses of your size and industry. The calculation typically uses three years of data, excluding the most recent completed policy year.
For example, if your current policy year is 2025, your mod is generally calculated using data from the 2021, 2022, and 2023 policy periods (though this can vary slightly by state and rating bureau).
A mod of 1.0 means your loss experience matches the industry average. Below 1.0 means better-than-average, above 1.0 means worse.
The calculation is performed by your state’s rating bureau or the National Council on Compensation Insurance (NCCI) for the states they govern (currently around 35 states plus D.C.).
How Your Mod Affects Your Premium
The math is straightforward:
Base Premium x Experience Mod = Modified Premium
If your base premium is $50,000 and your mod is 1.15, you pay $57,500. Drop that mod to 0.95 and you pay $47,500. That’s a $10,000 annual difference from a 0.20 swing in your mod.
Over the three-to-four years that data stays on your mod worksheet, a single error can cost tens of thousands of dollars in excess premium.
5 Common Reasons Your Experience Mod Is Wrong
1. Claims That Don’t Belong to You
Sometimes claims from another employer end up on your mod worksheet. This happens more often than you’d think, especially if:
- Your company has a common name
- You’ve changed insurance carriers
- Your policy was part of a group or association program
- There were data entry errors at the rating bureau
Even one claim that isn’t yours can spike your mod significantly.
2. Inflated Claim Reserves
Insurance adjusters set “reserves” on open claims — their estimate of what the claim will ultimately cost. These reserves flow directly into your mod calculation.
The problem? Reserves are often set conservatively high as a precaution. An adjuster might reserve $75,000 on a claim that ultimately settles for $20,000. But if that inflated reserve hits your mod worksheet before the claim closes, you’re paying premium based on losses that may never materialize at that level.
The timing matters too. Your mod uses claim values as of a specific “unit statistical date” — typically several months before your policy renewal. If reserves are inflated at that snapshot, your mod suffers regardless of what happens later.
3. Payroll Reported Under Wrong Class Codes
Your mod calculation uses “expected losses” based on your payroll by classification. If your payroll was reported under a higher-risk class code than your actual operations warrant, your expected losses will be skewed — and your mod along with it.
This is a double hit: you’re already overpaying on misclassified premium, AND the misclassification is distorting your mod calculation for years to come.
4. Subrogation Recoveries Not Credited
When a workplace injury is caused by a negligent third party — say an employee is rear-ended while driving for work — your insurance carrier may recover money from the at-fault party through subrogation.
Those recoveries should reduce the claim amount on your mod worksheet. But in many cases, the recovery is never reported to the rating bureau. The full claim amount stays on your record, keeping your mod artificially high.
5. Policy Cancellations and Rewrites Affecting Timing
If your workers’ comp policy was canceled and rewritten mid-term (common when switching carriers), the timing can cause claims to stay on your mod longer than they should.
A policy that should have rolled off your three-year experience window might remain on your mod due to how split policy periods are counted by the rating bureau. This is a technical error that most employers would never catch on their own.
Signs Your Experience Mod May Be Wrong
Before diving into the full verification process, here are warning signs that your mod may contain errors:
- Your mod increased significantly without any new claims
- You have open claims from several years ago that should have been resolved
- You’ve changed carriers or had policy rewrites in the past few years
- Your mod seems high relative to your actual claims history
- You’ve had workplace injuries caused by third parties
- You’ve never had your mod worksheet independently reviewed
How to Check If Your Mod Is Wrong
Step 1: Get Your Mod Worksheet
Request your experience rating worksheet from your state’s rating bureau or NCCI. As an employer, you have the right to obtain this document. It shows every claim, every payroll amount, and every calculation used to arrive at your mod. Your agent or broker can also request it on your behalf.
Step 2: Compare Claims to Your Records
Match every claim on the worksheet against your own records:
- Do you recognize all listed claims?
- Do the dollar amounts match what you know about each claim?
- Are any closed claims still showing open reserves?
- Were any claims caused by a third party (potential subrogation)?
Step 3: Verify Your Payroll by Classification
Compare the payroll figures on your mod worksheet against your actual premium audits for those years. The numbers should match. If they don’t, someone reported incorrect data to the rating bureau.
Step 4: Calculate Your Minimum Mod
Every company has a “minimum mod” — the lowest possible rating you’d have with zero claims during the experience period. If your current mod is significantly higher than your minimum, understand exactly which claims are driving the gap. Are those claims accurate?
Step 5: Check the Math
The mod formula itself can be verified. While the calculation is complex, the inputs (payroll, claims, expected loss rates) are all on your worksheet. Errors in the formula application are rare but not unheard of.
How to Fix a Wrong Experience Mod
If you find errors, you have several options:
- File a dispute with the rating bureau. NCCI and state bureaus have formal dispute processes. You’ll need documentation supporting the correction.
- Work with your insurance carrier. If claim reserves are inflated, your broker or agent can contact the adjuster to request a reserve review before the next unit statistical reporting date.
- Correct classification errors. If payroll was reported under wrong class codes, file corrected unit statistical data through your carrier.
- Request subrogation credits. If your carrier recovered money from a third party, ensure those recoveries were reported to reduce the claim on your mod.
- Hire a specialist. Experience mod corrections involve navigating rating bureau procedures, insurance carrier bureaucracy, and complex actuarial formulas. A workers’ comp premium recovery specialist knows exactly where to look and how to get corrections processed efficiently.
What Documents Should You Gather?
If you’re going to review your mod (or have a specialist review it), collect these documents:
- Experience modification worksheet (from NCCI or your state bureau)
- Loss runs from your carrier for the past 5 years
- Premium audit worksheets for the past 5 years
- Policy declarations pages for the same period
- Records of any third-party claims (auto accidents, premises liability, etc.)
- Subrogation recovery documentation if applicable
Real-World Example
A manufacturing company with 85 employees had watched their mod climb from 1.05 to 1.28 over four years. Their broker attributed it to “a couple of bad claims years.” When we reviewed their mod worksheet, we found a $68,000 claim that belonged to a different insured with a similar name, and $31,000 in subrogation recoveries that were never credited to reduce two other claims.
After filing corrections with the rating bureau, their mod dropped to 1.04. The company received refunds on three years of overpaid premium totaling $47,000, and their annual premium going forward decreased by approximately $19,000.
(Details anonymized to protect client privacy)
The Timeline for Corrections
Mod corrections can typically be applied retroactively, meaning you may be entitled to refunds on premium you’ve already paid based on the incorrect mod. Depending on your state, you could recover overpayments going back several years.
The sooner you act, the more you can recover — and the sooner your corrected mod starts saving you money on future premiums.
Frequently Asked Questions
How often should I review my experience mod?
At minimum, review your mod worksheet annually before your policy renewal. This gives you time to identify and dispute errors before they affect your next premium. Many businesses benefit from having a specialist review it every year.
Can my experience mod go below 1.0?
Yes. A mod below 1.0 means your loss experience is better than the industry average. Many well-managed businesses maintain mods in the 0.70-0.90 range. The lower your mod, the less you pay in workers’ comp premium.
How long does a mod correction take?
Simple corrections (like removing a claim that doesn’t belong to you) can be processed in a few weeks. More complex issues involving multiple years or multiple types of errors may take several months to fully resolve.
Will fixing my mod affect my relationship with my insurance carrier?
No. Mod corrections are handled through the rating bureau, not your carrier. Your carrier benefits from accurate data too. A corrected mod simply means your premium accurately reflects your actual risk.
Don’t Guess — Get a Free Mod Review
At Comp Recover, we analyze your experience modification rate as part of our comprehensive premium review. We pull your mod worksheets, verify every claim and payroll figure, and identify any errors inflating your rate.
If we find your mod is wrong, we handle the entire correction process — from filing disputes with the rating bureau to recovering your overpaid premiums. If we don’t find savings, you pay nothing.
Request a free experience mod review and find out if your experience modification rate has been costing you more than it should.
Note: Experience modification rate calculations and dispute procedures vary by state and rating bureau. This article provides general information and may not apply to all jurisdictions. This is not legal or insurance advice.
Last updated: January 2026