Workers' Compensation Insurance in California
In California, almost every business with employees is legally required to carry workers' compensation insurance — even with one part-time employee. It pays medical bills and lost wages when an employee is hurt on the job, and it protects the employer from most injury lawsuits. This guide explains who's required to carry it, what it covers, how your premium and X-Mod are calculated, how to lower your cost, and how to get a 24-hour quick quote.
Who is required to carry it in California?
Under California Labor Code §3700, employers with one or more employees must carry workers' compensation coverage. Key points:
- One employee triggers it — full-time, part-time, or seasonal.
- Roofers must carry coverage even with no employees (C-39 license requirement).
- Sole proprietors and certain officers/owners can sometimes be excluded with a proper election, but a working owner who excludes themselves may be left without coverage for their own injuries.
- Uninsured subcontractors can be picked up as your employees at audit — collect certificates of insurance from every sub.
Going without required coverage can bring stop orders and significant penalties from the California Division of Workers' Compensation.
What does it cover?
- Medical treatment for work-related injuries and illnesses
- A portion of lost wages while the employee recovers
- Permanent disability and, in the worst cases, death benefits
- Employer's liability — defense and damages for injury-related lawsuits outside the no-fault system
How is the premium calculated?
California workers' comp premium follows a simple formula, then adjusts for your loss history:
| Component | What it means |
|---|---|
| Class code | A WCIRB classification for the type of work (e.g., clerical vs. roofing). Each has its own rate. |
| Payroll | Premium is figured per $100 of payroll in each class code. |
| Rate | The cost per $100 of payroll for that class, varying widely by hazard. |
| Experience Mod (X-Mod) | A multiplier from your past claims. Below 1.00 is a credit; above 1.00 is a surcharge. |
In short: (payroll ÷ 100) × rate × X-Mod, summed across your class codes. Misclassified payroll and a high X-Mod are the two biggest drivers of overpaying.
What makes my cost go up or down?
- Your class codes and how payroll is split — especially where dual-wage rules apply (carpentry, electrical, plumbing).
- Your X-Mod — driven by claim frequency and severity over prior years.
- Owner inclusion/exclusion and how subcontractor labor is handled.
- Safety and return-to-work programs — documented programs reduce claim cost and, over time, your X-Mod.
How to lower your workers' comp cost
- Keep payroll cleanly separated by class code, and maintain dual-wage records where required.
- Collect certificates of insurance from every subcontractor so they aren't added to your payroll at audit.
- Run a written return-to-work / light-duty program to shorten claims.
- Review your X-Mod worksheet for reserve or reporting errors that can be corrected with the WCIRB.
- Track overtime so it can be reduced to straight-time wage at audit.
How to get a workers' comp quote (step by step)
- Have your class code(s) or a description of the work, your business structure, and employee count ready.
- Know your estimated annual payroll (by class code if you have more than one).
- Note any owners/officers to include or exclude, and whether you use subcontractors.
- Gather three years of loss history and your current X-Mod if you have it.
- Start the 24-hour workers' comp quick quote — or call (714) 988-3863 and a licensed advisor will build it with you.
We offer a 24-hour quick quote for workers' comp.
Frequently asked questions
Do I need workers' comp for one part-time employee in California?
Yes. California requires workers' compensation once you have any employee, including part-time and seasonal workers.
Can owners exclude themselves from coverage?
Certain officers, members, or partners can elect to be excluded, but a working owner who excludes themselves may have no coverage for their own on-the-job injuries. Confirm the right choice with a licensed advisor.
What is an X-Mod and why does mine matter?
The experience modification adjusts your premium based on past claims versus what's expected for your size and class. Below 1.00 lowers your premium; above 1.00 raises it. Accurate class codes and a return-to-work program help keep it low.
Will uninsured subcontractors affect my premium?
Yes. At audit, uninsured subcontractors can be added to your payroll and charged premium. Always collect certificates of insurance from your subs.
Focus West Insurance Solutions is a licensed brokerage (CA Lic. #0M32679). This guide is general information, not legal, tax, or coverage advice; requirements and rates vary by operation, class code, and carrier underwriting. A quick quote is an automated benchmark a licensed advisor verifies, not an offer or binding of insurance. Sources: California Department of Industrial Relations / Division of Workers' Compensation; WCIRB California. Related: insurance glossary · contractor insurance · WC quick quote.