Every workers’ comp premium starts with classification: your operations are assigned codes, each with a rate per $100 of payroll, and everything else — mods, credits, dividends — multiplies from there. Misclassification is the most common premium error in the industry, in both directions: businesses overpaying for years on codes that don’t fit, and businesses underpaying toward an audit bill. These guides cover the codes we see most.

Class code guides

8810 — Clerical Office Employees

5551 — Roofing

5645 — Residential Carpentry

7219 — Trucking

9082 — Restaurants

8835 — Home Health Care

9014 — Janitorial Services

0042 — Landscaping

8017 — Retail Stores

5537 — HVAC Installation & Service

How classification actually works

Most states use the NCCI classification system; Pennsylvania, Delaware, New Jersey, and a few others run their own bureaus with parallel structures. Your business gets a governing class for its main operation, standard exception codes (like 8810 clerical) can apply where records support them, and payroll splits between codes are allowed — or disallowed — based on state rules and the quality of your records. The premium mechanics are covered in our guide to how workers’ comp premiums are calculated.

Class code FAQs

What is a workers’ comp class code?

A classification code assigns your business operations to a category with a rate per $100 of payroll reflecting that work’s injury risk. Most states use NCCI’s system; some run their own bureaus with similar structures. Your premium is essentially payroll × class rate × experience mod, so the code assignment is the foundation of the whole calculation.

Who assigns my class codes?

Your insurance carrier assigns codes based on your described operations — and verifies them at audit. Businesses can dispute classifications through their carrier and state mechanisms, and an independent agent who documents your operations correctly at the start prevents most disputes.

Can wrong class codes really change my premium that much?

Dramatically. The spread between clerical (often under $1 per $100 of payroll) and roofing (often past $20) is the widest in insurance. Even adjacent trade codes can differ by half — misclassification is the most common overcharge we find, and the most common audit bomb.

How do I find my business’s class code?

Start with our guides above, then have us review your operations — the correct answer depends on exactly what your crews do, how your payroll records separate work, and your state’s system. Reviews are part of every quote we run.