What is California Comp Authority?

California Comp Authority has 25 pages. See its app structure and page count in a summary based only on verified setup data.

What is the average cost of workers' comp in California?

There is no single average—cost depends on payroll, class code, and experience mod. A clerical account pays far less per $100 of payroll than a roofing account.

Is there a minimum premium?

Many carriers impose a minimum premium regardless of payroll size, which matters most for very small or new businesses.

Can I lower my premium if I have claims?

Yes, over time. Fewer future claims, correct classification, and a return-to-work program improve the experience mod and reduce premium in subsequent years.

How Much Does Workers' Compensation Insurance Cost in California?

California workers' comp cost depends on payroll, class code, experience modification, and claims history. Here's how premium is calculated and what moves it up or down.

Last reviewed 2026-09-01•By CA Workers' Comp•Reviewed by Editorial Team

Key Takeaways

Premium = (Payroll ÷ 100) × Class Code Rate × Experience Mod, plus other factors.
High-hazard industries like roofing and trucking carry much higher base rates.
The experience mod can raise or lower premium significantly.
Accurate payroll and classification prevent audit surprises.
Safety and return-to-work programs are the biggest long-term cost reducers.

What Determines Workers' Comp Cost in California?

Three factors drive most of the cost: payroll, the class-code rate, and the experience modification. Additional underwriting factors—credits, debits, minimum premiums, assessments, and expenses—also apply. No two businesses pay the same because the combination is unique.

The Basic Premium Formula

Estimated Base Premium = Payroll ÷ 100 × Rate. Estimated Modified Premium = Base Premium × Experience Modification Factor. This is an estimate only; actual premium depends on carrier underwriting, classifications, claims, and other rating factors.

Why Some Industries Cost More

Base rates reflect hazard. Roofing, trucking, and construction carry high rates because claims are frequent and severe. Clerical and professional-services codes carry low rates. A business with multiple operations pays each code's rate on its share of payroll.

How the Experience Mod Affects Cost

A mod below 1.00 lowers premium; a mod above 1.00 raises it. Because high-hazard codes have high base rates, the mod has a larger dollar effect there. Improving the mod through fewer and less severe claims is one of the most effective cost controls.

How to Lower Your Premium

Reduce claims with safety and return-to-work programs, verify correct class codes, manage payroll reporting, improve your experience mod, and shop the market with a broker. Even high-hazard or hard-to-place accounts can often find competitive options.