Updated January 8, 2026 · 12 min read
California Contractor License Classifications (A, B, B-2, C-Series)
CSLB issues three top-level classifications — A, B, B-2 — plus 40+ C-series specialty classes. Picking the wrong one is the most expensive mistake in the application process: it forces a new application, new fee, and new trade exam. This is the working scope of each class.
Class A — General Engineering
Fixed-works projects requiring specialized engineering: highways, bridges, dams, tunnels, water systems, sewers, railroads. Broadest scope for civil work but does NOT cover building construction unless incidental.
Class B — General Building
Any structure built or to be built requiring two or more unrelated trades. The most common license for GCs. Can subcontract specialty work but must self-perform at least one trade on residential jobs.
Class B-2 — Residential Remodeling
New CSLB class as of 2024. Limited to remodeling existing single-family/multi-family residences requiring three or more unrelated trades. Cannot do new construction, structural, or work over $50k that requires a full B.
C-Series specialties
40+ individual trades: C-8 concrete, C-10 electrical, C-15 flooring, C-20 HVAC, C-27 landscaping, C-33 painting, C-36 plumbing, C-38 refrigeration, C-39 roofing, C-54 tile, and many more. Each is limited to that trade and directly related work.
Applies to these licenses
Frequently asked
Can I hold multiple classifications?
Yes. File Form 13A-3, take the extra trade exam(s), pay a small fee. No new application fee if the same entity holds the license.
Which class do I need to build a house?
Class B if you're the general contractor. Subcontractors on the same project each hold their own C-series.
What's the difference between B and B-2?
B allows new construction and any building work with two-plus trades; B-2 is remodel-only, three-plus trades, and capped at residential.
Ready to prep for your CSLB exam?
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