Massachusetts Workers' Comp Rate Calculator

Workers' comp in Massachusetts: what's different

Massachusetts has no state fund option. Chapter 152 lets employers cover workers through a private insurer, a self-insurance group, or a self-insurer license from the Department of Industrial Accidents (DIA). Rates come from the Workers' Compensation Rating and Inspection Bureau of Massachusetts (WCRIBMA), not NCCI.

Who must carry coverage

The DIA says every employer operating in Massachusetts must cover its employees, no matter how many people it employs or how many hours they work. DIA guidance adds that family members get no exemption, and a 1099 does not by itself exclude a worker.

The exceptions are limited:

• Domestic workers. Coverage is elective for a domestic worker who works for you less than 16 hours a week.
• Corporate officers. An officer or director who owns at least 25% of the stock can opt out by filing a written waiver (DIA Form 153). DIA guidance allows at most four exempt people.
• LLC members, LLP partners, and sole proprietors do not need coverage for themselves. However, their employees must be covered.
• Out-of-state employers must cover everyone working in Massachusetts. If Massachusetts appears only under item 3C of the policy, the insurer must file DIA Form 154.

A DIA self-insurer license is renewed annually and requires a deposit or bond of at least $20,000 plus reinsurance.

Who sets rates

The DIA does not set rates or class codes. WCRIBMA files rates and classifications with the Commissioner of Insurance on behalf of its member insurers. The Commissioner holds a hearing, and no new rates take effect until approved.

The Commissioner ordered a 14.6% average rate cut effective July 1, 2024. On May 15, 2025, the Commissioner disapproved WCRIBMA's request for a 7.1% average increase, so the 2024 rates stayed in effect. When we checked in October 2026, WCRIBMA's site showed no later general rate change. Insurers may also use approved deviations and schedule rating.

Class codes come from the Massachusetts Workers' Compensation and Employers Liability Insurance Manual and may differ from NCCI codes used elsewhere. In WCRIBMA's rate table, Roofing NOC is code 5545 and code 8831 is pet grooming.

Experience rating and merit rating

WCRIBMA issues mods for Massachusetts-only employers. NCCI issues interstate mods. You qualify for intrastate experience rating when the last two years of the experience period produce at least $11,000 of premium, or $5,500 a year on average if the period is longer. Employers with three years of data and an average annual premium of at least $500, but below that threshold, get merit rating instead. Losses above the expected level can add an ARAP (All Risk Adjustment Program) surcharge.

If no insurer will write you

An employer rejected by two insurers can appeal to the Commissioner, who designates an insurer. The Massachusetts Workers' Compensation Assigned Risk Pool handles these assignments, and the Commissioner has designated WCRIBMA to administer it. Pool policies use the same approved manual rates, but premium discount does not apply.

Penalties for going uninsured

The DIA issues a stop work order. Fines start at $100 a day, weekends and holidays included, until coverage starts and the fine is paid. If you appeal and the DIA finds you were uninsured, the fine is $250 a day. Criminal penalties reach a $1,500 fine, one year in jail, or both, plus a three-year ban from state and municipal contracts.

Your ongoing obligations

• Post the notice. Display the DIA "Notice to Employees" with your insurer, policy number, and contact person. DIA guidance cites a $100 fine for failing to post.
• Report injuries. If an injury keeps a worker from full wages for five or more calendar days, file Form 101 electronically with the DIA within seven calendar days, not counting Sundays and legal holidays. The clock starts on the fifth day of disability, or when you learn of the injury if later. Send copies to the employee and your insurer.
• Check coverage. The DIA's free Proof of Coverage search is at mapoc.org.

If an uninsured employer's worker is hurt, the Workers' Compensation Trust Fund may pay benefits, and the DIA then sues the employer to recover them.

Worked example: how the calculator estimates premium

Premium = (payroll / 100) × rate per $100 × experience mod

The rate below is WCRIBMA's published manual rate for code 5183 (Plumbing NOC), effective July 1, 2024. The payroll and mod are hypothetical.

• Annual payroll total: $400,000
• Code 5183 manual rate: $2.22 per $100
• Experience modifier: 0.90

Step by step

1. Payroll in hundreds: $400,000 / 100 = 4,000
2. Manual premium: 4,000 × $2.22 = $8,880
3. Apply the mod: $8,880 × 0.90 = $7,992

A real policy will differ. The WCRIBMA manual adds a $338 expense constant when standard premium is at least $1,000, which brings this example to $8,330. Your insurer may apply a deviation or premium discount, and a DIA assessment is added. The private insured assessment rate is 0.05688 for policies effective on or after July 1, 2026.

Frequently asked questions

Official sources

• DIA, Workers' Compensation Insurance Requirements
• DIA, Quick Start Guide to WC Insurance Requirements
• DIA, Employer's Guide to the Massachusetts Workers' Compensation System
• DIA Proof of Coverage search
• M.G.L. c.152, s.1 (definitions)
• M.G.L. c.152, s.6 (injury reports)
• M.G.L. c.152, s.25A (insurance and self-insurance)
• M.G.L. c.152, s.25C (stop work orders, penalties)
• M.G.L. c.152, s.53A (rate filings and approval)
• M.G.L. c.152, s.65 (Workers' Compensation Trust Fund)
• M.G.L. c.152, s.65A (assigned risk)
• WCRIBMA, 2025 Rate Filing timeline
• WCRIBMA, 2024 Rate Filing timeline
• WCRIBMA Circular Letter 2430 (July 1, 2024 rate revision)
• WCRIBMA Circular Letter 2431 (manual rates by class, July 1, 2024)
• WCRIBMA Circular Letter 2445 (2025 filing disapproved)
• WCRIBMA Circular Letter 2446 (deviations, next filing)
• WCRIBMA Circular Letter 2455 (DIA assessment rates, July 1, 2026)
• WCRIBMA FAQs (experience rating, merit rating, pool, expense constant)
• WCRIBMA Assigned Risk Pool Plan of Operation
• WCRIBMA Class Code Lookup

Sources accessed 2026-10-16.

This is general information, not legal advice. Confirm details with the Massachusetts Department of Industrial Accidents.

Reviewer: Sam Newland, CFP, Founder of Benefitra. Last updated October 17, 2026. How the calculator works. Editorial policy.