California Plumbers Face New Workers' Comp Mandate by 2028—Here's What Changes

A Major Insurance Requirement Is Coming to California Plumbing

If you operate as a licensed plumber in California, a significant change is on the horizon. Beginning in January 2028, all plumbing contractors will be required to carry workers' compensation insurance, regardless of whether they currently employ staff. This marks a shift from the current rule, which mandates coverage only for contractors with employees.

For solo operators and owner-only businesses, this represents a new operational cost and compliance obligation to factor into your budget and business planning. The change affects how you structure insurance expenses and may influence your pricing model.

What This Means for Your Licensing and Bonding

To legally perform plumbing work exceeding $500 in labor and materials in California, you must hold a C-36 Plumbing Contractor license from the California Contractors State License Board (CSLB). This license comes with several requirements and costs that you should understand clearly.

The path to licensure requires four years of journey-level plumbing experience accumulated within the last decade. A relevant college degree can substitute for up to three years of that experience, though you must still complete at least one year of field-based work. You'll also need to be at least 18, possess a valid Social Security Number or ITIN, and have a high school diploma or equivalent.

The licensing process involves two exams—a Law and Business exam and a Trade exam—each requiring a minimum score of 70 percent to pass. The initial application fee is $450 and is non-refundable.

Initial and Renewal Costs Add Up

Once you pass your exams, your initial license fee depends on your business structure. Sole owners pay $200, while non-sole owners pay $350. These licenses must be renewed every two years, and renewal fees are substantially higher: $450 for sole owners and $700 for non-sole owners.

In addition to licensing fees, California requires a $25,000 contractor bond for obtaining and renewing your C-36 license. This bond protects consumers and is a non-negotiable part of licensure in the state.

It is worth noting that as of early 2026, California does not impose statewide continuing education requirements for plumbers to maintain their licenses. This differs from some other states and professions, which can help reduce your ongoing compliance burden.

Planning for 2028 and Beyond

The transition to mandatory workers' compensation insurance for all contractors—not just those with employees—represents a meaningful change in operating costs. You should begin evaluating insurance carriers and premium estimates now, rather than waiting until the deadline. Insurance costs vary by business size, claims history, and other factors, so early research will help you incorporate this expense into your financial projections.

For plumbers renewing licenses before January 2028, verify whether your renewal cycle aligns with the new insurance rule. Some contractors may face a renewal deadline shortly after the requirement takes effect, so plan accordingly to avoid compliance gaps.

Understanding the full cost of operating legally in California—licensing fees, renewal costs, bonding, and the upcoming insurance mandate—helps you set realistic pricing, manage cash flow, and maintain uninterrupted licensing status. Review your current license expiration date and insurance situation now to ensure a smooth transition when the new requirement arrives.