Experience Modification Factor for Cleaning Companies

The experience modification factor (EMR, or "the Mod") is a multiplier applied to your workers' compensation base premium. If your base premium is $40,000 and your Mod is 1.20, you pay $48,000. If your Mod is 0.85, you pay $34,000. The same $40,000 base premium costs $14,000 more for the company with a high Mod, and that gap compounds every year.

For a cleaning company with 20–50 employees, the EMR is often the largest single controllable variable in workers' comp cost. Base rates are set by state rating bureaus. Class codes are determined by job function. But the Mod is shaped by your own claims history, which means it responds to your safety program, your claims management practices, and your attention to the data NCCI uses to calculate it.

How the Mod Is Calculated

The experience modification factor is calculated by NCCI (or the applicable state rating bureau) using three years of your own payroll and loss data. The Mod compares your actual losses to the expected losses for a company of your size in your industry.

The formula has three components:

Actual primary losses: Claims up to the "split point" (currently $17,500 per claim under NCCI's 2013 update). Frequency is heavily weighted: many small claims hurt more than one large claim.

Actual excess losses: Losses above the split point, weighted at a discount. A $150,000 catastrophic claim contributes less per dollar to the Mod than 10 claims of $15,000 each.

Expected losses: Calculated from your total payroll by class code, multiplied by expected loss rates (ELRs) that represent industry-average loss frequency and severity. This is the benchmark your actual losses are compared against.

If your actual losses exceed your expected losses, your Mod rises above 1.00. If your actual losses are lower than expected, your Mod falls below 1.00.

The rating period: The Mod calculation uses losses from the three policy years ending one year before the current policy year. Example: a policy effective January 1, 2026 uses loss data from 2022, 2023, and 2024. The most recent policy year (2025) is excluded because it's not yet fully developed.

Why Frequency Matters More Than Severity

The Mod formula weights claim frequency more heavily than claim severity for losses below the split point. This is the NCCI design intention: frequent small claims predict future loss experience better than rare catastrophic events. The consequence for cleaning companies is significant:

One $50,000 claim contributes $17,500 of primary losses (capped at the split point) plus discounted excess losses. Its total impact on the Mod is moderate.

Ten $5,000 claims each contributes $5,000 of primary losses = $50,000 total primary losses: significantly more Mod impact than the single large claim.

This means that managing claim frequency (even small claims) is the highest-use activity for Mod control. Operators who address every injury with proper medical management, return-to-work programs, and investigation (even for minor claims) have systematically lower Mods than operators who only pay attention to large claims.

Disputing Errors in Your Mod Calculation

NCCI uses unit statistical data submitted by your carrier to calculate the Mod. If the carrier submits incorrect data (wrong payroll, wrong class code, overcounted losses, closed claims with open reserves) your Mod is overstated. These errors are more common than most operators realize.

Step 1: Request the unit statistical card (USR) from your broker. This is the data NCCI used to calculate your Mod; it shows payroll by code, losses by claim, reserves, and the experience period covered.

Step 2: Compare USR data to your records. Check:

• Is payroll by code accurate? (Compare to actual payroll by classification)
• Are closed claims still showing open reserves? (A claim that settled three years ago should not carry an open reserve)
• Are any claims included that are under first-notice-only status (reported but never developed into a real loss)?
• Are any losses from other insureds included on your unit statistical record? (Rare but possible error)

Step 3: File a correction request. If you identify errors, your broker can submit a correction to NCCI through the carrier. NCCI will recalculate the Mod based on corrected data. The revised Mod applies prospectively to your next policy.

Step 4: Request a "retro adjustment" if the corrected Mod would have applied to an expiring policy. Some states allow retroactive Mod corrections that result in return premium for prior policy years.

Impact on Government Contracts

Many government contracts and commercial facility management RFPs specify a maximum EMR threshold for bidder eligibility: typically 1.00 or below. Cleaning companies with Mods above 1.00 are disqualified from bidding. This creates a direct commercial consequence that extends beyond insurance cost: a high Mod restricts the contracts you can pursue.

If your Mod is above 1.00, working with a safety consultant to develop a structured loss prevention program is not optional; it's a competitive requirement for accessing higher-value government and institutional accounts.

The loss prevention guide covers the specific safety program elements that drive Mod reduction. The workers' comp classification codes guide explains how accurate class code assignment interacts with the Mod. The insurance hub is the full reference.

For official Mod calculation resources, NCCI's Experience Rating overview explains the plan mechanics for policyholders.