Workers' Comp Class Codes for California Contractors

The Foundation of Your Premium

In California, workers' compensation premiums are calculated using a simple formula: (Payroll / 100) × Class Code Rate × Experience Modifier (X-Mod). The Class Code Rate is determined by the Workers' Compensation Insurance Rating Bureau (WCIRB) based on the statistical risk of your specific trade.

Common Construction Class Codes

• 5403 - Carpentry: Covers rough framing and structural carpentry. High risk due to falls and saw injuries. High rate.
• 5432 - Carpentry (Cabinet Work): Covers interior finish carpentry and cabinet installation. Lower risk than framing. Lower rate.
• 5183 - Plumbing: Standard plumbing operations. Moderate rate.
• 5190 - Electrical Wiring: Standard electrical work. Moderate rate.
• 5474 - Painting: Exterior and interior painting. Moderate rate, but heavily impacted by height exposures.
• 5552 - Roofing: One of the highest risk codes in construction. Extremely high rate due to fall severity.
• 5201 - Concrete Work: Pouring and finishing. Moderate to high rate due to heavy lifting and machinery.
• 5606 - Executive Supervisors: For GCs or project managers who only supervise and do not pick up tools. Very low rate.

The Danger of Misclassification

It is tempting to classify your framing crew under 5432 (finish carpentry) to save money. Do not do this. When the carrier conducts their annual premium audit, they will discover the misclassification, reclassify your payroll retroactively, and send you a massive bill for the difference. Intentional misclassification is also insurance fraud.

Splitting Payroll

In California, you generally cannot split an employee's payroll between two construction class codes. If an employee spends 90% of their time doing finish carpentry and 10% doing rough framing, 100% of their payroll must be assigned to the higher-risk framing code (5403). The only exception is if you maintain strict, verifiable timecards detailing the exact hours spent on each task, and the carrier approves the division.