The three license groups
| Group | What it covers | Active licenses (CSLB, Sept 2026) |
|---|---|---|
| A — General Engineering | Fixed works that need specialized engineering knowledge, such as roads, bridges, tunnels, irrigation, drainage and pipelines | 13,954 |
| B — General Building | Building a structure or framework that involves at least two unrelated building trades | 98,102 |
| C — Specialty | One specific trade, such as C-10 Electrical, C-36 Plumbing or C-39 Roofing | About 127,000 licenses hold at least one C classification |
Note: Source: CSLB master license file, September 2026, licenses in good standing. A license can hold more than one classification, so the counts overlap.
What a B contractor cannot do
- A B contractor may not take a job that is only one trade or craft. That work needs the specialty C license, unless it is incidental to a larger building project
- A B contractor who wants to do a specialty on its own, such as electrical on a stand-alone job, must also hold that C license
Insurance and bond rules that apply to every class
- $25,000 CSLB contractor license bond for every active license
- LLC licenses also need a $100,000 employee/worker bond and $1M-$5M of liability insurance
- Starting January 1, 2028 (SB 216, as delayed by SB 1455), every active California contractor license must carry workers' comp, except joint ventures with no employees. Until then, C-8, C-20, C-22, C-39 and C-61/D-49 licenses must already carry it, and every other license needs it as soon as it has an employee.
Workers' comp today by group
| Group | Active licenses | Filed exempt | Workers' comp policy on file |
|---|---|---|---|
| B General Building | 98,102 | 56,038 (57%) | 40,071 (41%) |
| A General Engineering | 13,954 | 4,703 (34%) | 8,825 (63%) |
| C-20 HVAC | 10,980 | 0 | 10,753 (98%) |
| C-39 Roofing | 5,339 | 0 | 4,903 (92%) |
Note: Source: CSLB master license file, September 2026.
Which license fits your work
- Do one trade: get the C license for it
- Coordinate several trades on buildings: B General Building
- Build roads, utilities, pipelines or similar engineered works: A General Engineering
- Do residential remodels: ask CSLB about the B-2 Residential Remodeling classification, which covers remodel work on existing homes
Get the right coverage for your license
Liability, workers' comp and bond needs differ between a one-trade C contractor and a B general contractor with subs. Call (858) 925-9555 or request a review online — only your name, phone and email are required; we collect project details by phone. Asena Capital Insurance Services, CA License #6008596.
Frequently asked questions
What is the difference between an A, B and C contractor license?
A is General Engineering, B is General Building and C is a single specialty trade. B and A licenses are for contractors who coordinate several trades or engineered works.
Can a B contractor do electrical work?
A B contractor can include electrical as part of a larger building project that involves at least two unrelated trades. Stand-alone electrical work needs the C-10 Electrical license.
Do I need workers' comp for a B license?
Not today unless you have an employee. From January 1, 2028, every active California contractor license must carry workers' comp, except joint ventures with no employees.
Do general contractors need liability insurance?
CSLB requires it only for LLC licenses. In practice almost every owner and lender requires general liability from a general contractor.