A Massachusetts workers' comp class code is a number that places your business in a group of employers with similar work hazards. Your premium starts with the rate for that code, applied per $100 of payroll. Massachusetts does not use the national code book most states use. The Workers' Compensation Rating and Inspection Bureau of Massachusetts (WCRIBMA) classifies risks under its own manual, so the code you find on a generic website may not match your policy. This guide shows you how codes are assigned, where to look yours up, and what to do if yours looks wrong.
TL;DR
- Massachusetts classifies employers through the WCRIBMA, not the Department of Industrial Accidents and not the insurance carrier.
- One governing classification usually describes the whole business: the one producing the greatest payroll. Clerical staff (code 8810) and some distinct operations can be split out.
- Your code sets the manual rate per $100 of payroll. Your experience modification and other factors then adjust the final premium.
- You can look up codes and descriptions on the WCRIBMA site, and you can ask the bureau in writing to change a classification you believe is wrong.
- An independent agent can check your code against what your employees actually do before you bind a policy.
Table of Contents
- What a workers' comp class code is
- Who decides your code in Massachusetts
- How to look up your class code
- How the governing classification works
- Class codes for contractors and construction
- How your code affects your premium
- Multi-state employers
- How to correct a wrong class code
- Mistakes we see most often
- Our perspective on class codes
- Get your classification reviewed
- FAQ
- Sources
What a workers' comp class code is
Insurers cannot price a roofer and a bookkeeper the same way. Classification solves that. The classification system groups employers so that each classification's rate reflects the exposures common to the employers in it. A code is shorthand for that group, and every code has an official description (called a phraseology) that says what work it covers.
For you as an employer, the code matters for three reasons:
- It sets the base rate you pay on each $100 of payroll.
- It determines which of your employees are rated together and which are rated separately.
- It is what an auditor checks after the policy ends, when your actual payroll is compared against what you estimated.
If you are still working out whether you must carry coverage at all, start with our guide on who must carry workers' comp coverage, then come back here for the pricing mechanics.
Who decides your code in Massachusetts
Many employers assume the state workers' comp agency sets codes. It does not. The Department of Industrial Accidents does not establish insurance rates or classification codes, and it points employers to the WCRIBMA instead.
The WCRIBMA has full authority to classify workers' compensation risks in the state. It can inspect a risk and decide the proper classification under the manual's rules. Your carrier and your agent apply those rules when writing the policy, but neither can invent a code that the manual does not support.
Massachusetts codes versus NCCI codes
If you have read about class codes elsewhere, you were probably reading about NCCI codes. Massachusetts keeps its own Workers' Compensation and Employers Liability Insurance Manual for classification, even though it uses some NCCI materials such as the Experience Rating Plan Manual. The practical lesson: never copy a code from a national list or from a neighboring state's policy. Confirm it in the Massachusetts manual or the WCRIBMA lookup.
Code numbers can look alike across systems while the descriptions differ. Always read the phraseology, not just the number.
How to look up your class code
The WCRIBMA offers three free tools, all described on its class code lookup page:
- Class Code Lookup: search by code number or by words describing the work.
- Class Code Rate Download: a file of codes with their rates.
- Massachusetts Master Alphabetical Classification Index: a downloadable alphabetical list of operations and the codes that go with them.
A simple way to use them:
- Write down what your business actually does, in plain words (for example, "finish carpentry in occupied homes").
- Search the alphabetical index using those words and a few synonyms.
- Read the full phraseology of each candidate code, including any notes on what is included or excluded.
- Compare the result with the code on your current policy or quote.
If two codes both seem to fit, do not pick the cheaper one. The classification must follow the manual, and a wrong choice tends to surface at audit as a bill.
How the governing classification works
Most employers do many things. A landscaping company mows lawns, plows snow, and runs an office. The manual handles this with a governing classification. Generally, the governing classification, the one producing the greatest payroll, describes the entire business. That means a small amount of side work does not usually earn its own code.
There are exceptions, and they matter for your premium.
Standard exception classifications
Standard exceptions cover occupations common to many kinds of businesses. The best known is Clerical Office Employees, code 8810. Under the manual, these are not included in a business's basic classification unless it specifically says so, so a genuine office staff can be rated separately from field workers. The rate for clerical work is generally lower than for hazardous trades, which is why classification of office staff gets attention at audit.
Two cautions apply here. First, the office employees need to be truly clerical. A project manager who spends half the day on job sites is not a clerical employee just because the title sounds like office work. Second, keep payroll records by role so the split can be shown.
Distinct businesses
The manual also allows separate codes when a company runs distinct businesses, as the manual defines them. The rules are specific, so ask your agent to walk through the definition with your facts before assuming a second operation qualifies.
Class codes for contractors and construction
Construction is where classification gets the most scrutiny, and where we spend a lot of time with clients. The manual has dedicated rules for construction, often with separate classifications for individual trade operations. It also treats certain work as separate from your basic classification: for example, new construction or alterations performed by an insured's own employees are classified separately from the business's basic classification.
What this means in practice:
- A contractor who mainly does one trade may still have payroll for other work that needs its own code.
- A property owner or developer with its own crew doing building work can find that the construction work is rated separately from the core business.
- Subcontractor arrangements affect who carries the coverage and who shows up on your audit. Certificates from subcontractors should be collected and filed.
If you build or renovate, review your general liability and project coverage at the same time. Our builders risk insurance covers the structure under construction, while workers' comp covers your people. They answer different questions, and a lender or owner will often ask for both.
A worked example
Suppose a remodeling company has six carpenters, one estimator who is on site most days, and two people in the office handling billing and scheduling. The governing classification is the carpentry or remodeling code that produces the most payroll. The two office employees can be rated under code 8810 if they are truly clerical. The estimator is the debatable one: an employee who regularly works at job sites is usually not treated like a pure office worker. Settle that before the policy is written, not at audit.
This is an illustration of how the rules fit together, not a quote. Your actual classification depends on the manual's wording for your operations.
How your code affects your premium
The code is the foundation of the price. The manual rate is the amount charged per $100 of payroll for that classification. Other elements then shape the final number:
- Your experience rating modification, which compares your loss history to that of similar employers.
- Non-ratable elements and disease loadings that appear in the premium calculation.
- The rates themselves, which the WCRIBMA files and the Commissioner of Insurance approves.
Rates are revised on a schedule. For instance, revised manual rates and rating values took effect July 1, 2024 through Circular Letter 2432. Check the WCRIBMA site for the rates that apply to your policy's effective date, because the figures on any page you read, including this one, can be out of date.
A simple premium illustration
The formula is easy to see with made-up numbers. If a code had a rate of $5.00 per $100 and you reported $200,000 of payroll in that code, the base premium would be $10,000 before modification and other factors. If $40,000 of that payroll belonged to clerical staff under a lower-rated code, the split changes the math. Those numbers are invented to show the arithmetic and are not real Massachusetts rates.
Multi-state employers
If your crews or employees work in more than one state, classification is only one piece. Each state may use a different classification system, and payroll has to be allocated correctly. Payroll tax obligations also change from state to state, and this overview of multi-state payroll taxes is a good starting point for the employer-side paperwork. Your workers' comp policy should list every state where you have employees, and your agent should confirm how each is rated.
How to correct a wrong class code
A wrong code can raise your premium or leave you exposed to a surprise audit bill. Massachusetts gives you a route to fix it. An insured or carrier may submit a written request directly to the WCRIBMA to change a classification or rate on the ground that the risk was improperly classified. The request can be made during the policy term or within twelve months after the policy expires.
A clean request tends to include:
- Your policy number and the code currently assigned.
- The code you believe is correct, with the manual's phraseology quoted.
- A plain description of the work each group of employees does.
- Payroll records by role for the policy period.
- Job descriptions, contracts, or photos that show the operations.
The bureau may inspect the risk and decide the proper classification under the manual's rules, so be ready for a visit or follow-up questions. If you disagree with how an audit was handled, ask your agent to help you organize the records before you respond.
Mistakes we see most often
- Rating everyone as clerical. Field supervisors and estimators often do not qualify.
- Ignoring payroll changes. If you add a crew or a new line of work mid-term, tell your agent. Waiting for audit makes the correction larger.
- Using an old code. Copying last year's code or another state's code can carry an outdated classification into a new policy.
- Poor records. Without payroll by role, you cannot support a split between classes.
- Skipping the lookup. A ten-minute search of the WCRIBMA tools prevents most disputes.
Our perspective on class codes
Class codes look like a technical detail, but they are where a lot of workers' comp money is won or lost. We see it often: a business owner gets a quote, sees a code they do not recognize, and assumes it must be right because it came from an insurer.
Because we are an independent agency, we are not tied to one carrier's appetite. We shop your risk with the classification question in front of us, and we read the Massachusetts manual alongside your real operations: who is in the field, who is in the office, and what each person does all day. That conversation, with a licensed agent who knows the local market, is worth more than any online code list.
For contractors and developers especially, we pair workers' comp with the rest of the program, including general liability and builders risk, so the coverage fits the way you actually work. Our approach is to get the code right at the start, document it, and revisit it when your payroll or services change.
Mike
Get your classification reviewed
If you are renewing, expanding, or buying your first policy, we can review your operations against the Massachusetts classification rules and help you compare options. Our business insurance page covers workers' compensation, general liability, commercial property, business owner's policies, commercial auto, and professional liability, all from one independent agency.
Bring your current policy or quote and a short description of your crews. We will look at the classification, the payroll split, and the coverage around it.
FAQ
Does the Department of Industrial Accidents assign my class code?
No. The Department of Industrial Accidents does not set insurance rates or classification codes. The WCRIBMA has the authority to classify risks in Massachusetts under the manual, and your insurer applies that classification when it writes your policy.
Can one business have more than one class code?
Yes, in some cases. The governing classification, the one with the greatest payroll, generally describes the whole business. Standard exceptions such as clerical office employees (code 8810) and distinct businesses, as the manual defines them, can receive separate codes under its rules.
Where do I find the official description for my code?
Use the WCRIBMA class code lookup, the rate download, or the Master Alphabetical Classification Index. Read the full phraseology, not only the code number, because it states what work the code covers.
How long do I have to challenge a wrong classification?
An insured or carrier can send a written request to the WCRIBMA during the policy term or within twelve months after the policy expires. The request should say why the risk was improperly classified and include records that support it.
Are Massachusetts class codes the same as NCCI codes?
Not necessarily. Massachusetts maintains its own classification manual, even though it uses some NCCI materials in other areas such as experience rating. Check the Massachusetts manual before relying on a code from another state.
Sources
- WCRIBMA: Classification System
- Mass.gov: Workers' Compensation Insurance Rates and Codes
- WCRIBMA: Class Code Lookup
- Massachusetts Workers' Compensation and Employers Liability Insurance Manual
- Massachusetts Manual, version January 1, 2024
- WCRIBMA Circular Letter 2432: Manual Rates and Rating Values Effective July 1, 2024