California contractor license classes: all 46 CSLB classifications
CSLB lists 46 contractor license classifications: A, B and B-2, 42 specialty classes and C-61 Limited Specialty, plus 2 certifications (ASB and HAZ). 45 of the 46 have a CSLB trade exam, taken on top of the Law and Business exam; C-61 does not. PrepPass has free practice for 15 of them.
Data read November 7, 2026 from CSLB's classification pages, its Examination Study Guides page and the CSLB Data Portal. Active license counts are licenses with CLEAR status on that date. Check CSLB for current rules. PrepPass is independent of CSLB. Every applicant also needs the Law and Business exam.
General contractor classifications
Classes A, B and B-2 cover whole projects rather than a single trade.
A General Engineering Contractor
Builds fixed works that need specialized engineering skill, such as roads, bridges, pipelines, dams, sewers, utility plants and the grading/paving/concrete tied to them.
Trade exam: yes · Free practice, study guide, cheat sheet · 14,691 active licenses (CSLB Data Portal, read November 7, 2026)
B General Building Contractor
Builds or superintends structures for shelter or support that use at least two unrelated building trades; limits apply to prime contracts and to C-16 and C-57 work.
Trade exam: yes · Free practice, study guide, cheat sheet · 103,198 active licenses (CSLB Data Portal, read November 7, 2026)
B-2 Residential Remodeling Contractor
Takes contracts to improve existing residential wood-frame structures when the job uses three or more unrelated trades, without structural changes or system work beyond minor fixture-related alterations.
Trade exam: yes · No PrepPass material yet · 1,678 active licenses (CSLB Data Portal, read November 7, 2026)
Specialty classifications (C)
One class per trade, from C-2 to C-60. Each has its own CSLB trade exam on top of Law and Business.
C-2 Insulation and Acoustical Contractor
Installs insulation and preformed acoustical materials for temperature or sound control.
Trade exam: yes · No PrepPass material yet · 1,172 active licenses (CSLB Data Portal, read November 7, 2026)
C-4 Boiler, Hot Water Heating and Steam Fitting Contractor
Installs, services and repairs power boilers, hot-water heating systems, steam fitting and their associated equipment.
Trade exam: yes · No PrepPass material yet · 688 active licenses (CSLB Data Portal, read November 7, 2026)
C-5 Framing and Rough Carpentry Contractor
Does form work, framing and rough carpentry for framed structures, including subfloors, sheathing, siding, roof decking and trusses.
Trade exam: yes · No PrepPass material yet · 1,028 active licenses (CSLB Data Portal, read November 7, 2026)
C-6 Cabinet, Millwork and Finish Carpentry Contractor
Fabricates and installs cabinets, millwork, doors, trim and other finish carpentry items.
Trade exam: yes · Free practice, study guide, cheat sheet · 4,219 active licenses (CSLB Data Portal, read November 7, 2026)
C-7 Low Voltage Systems Contractor
Installs and maintains energy-limited communication and low-voltage systems up to 91 volts, excluding low-voltage fire alarm systems.
Trade exam: yes · Free practice, study guide, cheat sheet · 4,668 active licenses (CSLB Data Portal, read November 7, 2026)
C-8 Concrete Contractor
Forms, places, finishes and installs concrete work such as flatwork, paving and mass concrete.
Trade exam: yes · Free practice, study guide, cheat sheet · 5,302 active licenses (CSLB Data Portal, read November 7, 2026)
C-9 Drywall Contractor
Lays out and installs gypsum board assemblies with non-structural metal framing, and tapes and textures the finished surfaces.
Trade exam: yes · Free practice, study guide, cheat sheet · 3,176 active licenses (CSLB Data Portal, read November 7, 2026)
C-10 Electrical Contractor
Installs and connects wiring, fixtures, equipment and raceways that generate, transmit or use electrical energy, including PV cells.
Trade exam: yes · Free practice, study guide, cheat sheet · 28,094 active licenses (CSLB Data Portal, read November 7, 2026)
C-11 Elevator Contractor
Fabricates, installs and repairs elevators and their machinery, controls and related equipment.
Trade exam: yes · No PrepPass material yet · 213 active licenses (CSLB Data Portal, read November 7, 2026)
C-12 Earthwork and Paving Contractors
Digs, moves and places earth for cuts, fills, grades and trenches (explosives included) and places paving and surfacing materials.
Trade exam: yes · No PrepPass material yet · 2,426 active licenses (CSLB Data Portal, read November 7, 2026)
C-13 Fencing Contractor
Builds and repairs fences, gates, railings, guard rails, game-court enclosures and similar barriers, but not masonry walls.
Trade exam: yes · No PrepPass material yet · 1,826 active licenses (CSLB Data Portal, read November 7, 2026)
C-15 Flooring and Floor Covering Contractors
Prepares surfaces and installs carpet, resilient, wood and other flooring materials except ceramic tile.
Trade exam: yes · Free practice, study guide, cheat sheet · 6,702 active licenses (CSLB Data Portal, read November 7, 2026)
C-16 Fire Protection Contractor
Lays out, fabricates and installs fire protection systems and their equipment, excluding electrical alarm systems.
Trade exam: yes · No PrepPass material yet · 2,209 active licenses (CSLB Data Portal, read November 7, 2026)
C-17 Glazing Contractor
Cuts, assembles and installs glass, mirror and glass-substitute products and the frames, panels, sashes and doors that hold them.
Trade exam: yes · No PrepPass material yet · 3,041 active licenses (CSLB Data Portal, read November 7, 2026)
C-20 Warm-Air Heating, Ventilating and Air-Conditioning Contractor
Fabricates, installs and services warm-air heating, ventilating and air-conditioning systems with their ducts, controls and filters, including solar-assisted systems.
Trade exam: yes · Free practice, study guide, cheat sheet · 11,626 active licenses (CSLB Data Portal, read November 7, 2026)
C-21 Building Moving/Demolition Contractor
Raises, lowers, underpins, moves or demolishes structures and their foundations, but does not rebuild retained portions.
Trade exam: yes · No PrepPass material yet · 1,811 active licenses (CSLB Data Portal, read November 7, 2026)
C-22 Asbestos Abatement Contractor
Contains, encapsulates, removes and disposes of asbestos-containing construction materials under Cal/OSHA (DOSH) rules; DOSH registration required.
Trade exam: yes · No PrepPass material yet · 312 active licenses (CSLB Data Portal, read November 7, 2026)
C-23 Ornamental Metal Contractor
Fabricates and installs decorative metalwork for the architectural treatment of structures, not sheet metal work.
Trade exam: yes · No PrepPass material yet · 1,060 active licenses (CSLB Data Portal, read November 7, 2026)
C-27 Landscaping Contractor
Builds, installs and maintains landscape systems for gardens and grounds, including grading for planting, hardscape and irrigation.
Trade exam: yes · Free practice, study guide, cheat sheet · 12,092 active licenses (CSLB Data Portal, read November 7, 2026)
C-28 Lock and Security Equipment Contractor
Installs and services doors, locks, exit devices, safes, vaults and electronic access-control systems, excluding fire alarms.
Trade exam: yes · No PrepPass material yet · 366 active licenses (CSLB Data Portal, read November 7, 2026)
C-29 Masonry Contractor
Installs brick, block, stone and similar masonry units for walls, veneers, paving and refractory work.
Trade exam: yes · No PrepPass material yet · 2,030 active licenses (CSLB Data Portal, read November 7, 2026)
C-31 Construction Zone Traffic Control Contractor
Sets up and removes lane closures, flagging and traffic diversions on roadways using portable devices.
Trade exam: yes · No PrepPass material yet · 474 active licenses (CSLB Data Portal, read November 7, 2026)
C-32 Parking and Highway Improvement Contractor
Applies coatings, striping, markers, signs, wheel stops and similar items on paved surfaces, without re-paving.
Trade exam: yes · No PrepPass material yet · 497 active licenses (CSLB Data Portal, read November 7, 2026)
C-33 Painting and Decorating Contractor
Prepares surfaces and applies paints, coatings, wall coverings and similar finishes to structures.
Trade exam: yes · Free practice, study guide, cheat sheet · 15,437 active licenses (CSLB Data Portal, read November 7, 2026)
C-34 Pipeline Contractor
Fabricates and installs pipelines for fluids or protective conduits, including the trenching, backfill and resurfacing they need.
Trade exam: yes · No PrepPass material yet · 538 active licenses (CSLB Data Portal, read November 7, 2026)
C-35 Lathing and Plastering Contractor
Installs lath and metal studs and applies plaster or stucco coatings; the former C-26 Lathing class was merged into it in 1998.
Trade exam: yes · No PrepPass material yet · 1,810 active licenses (CSLB Data Portal, read November 7, 2026)
C-36 Plumbing Contractor
Provides safe water supply and waste disposal systems, gas piping and appliances, water heaters and related devices in structures.
Trade exam: yes · Free practice, study guide, cheat sheet · 17,582 active licenses (CSLB Data Portal, read November 7, 2026)
C-38 Refrigeration Contractor
Builds, installs and services refrigeration equipment and refrigerated spaces that hold temperatures below 50 °F.
Trade exam: yes · No PrepPass material yet · 1,592 active licenses (CSLB Data Portal, read November 7, 2026)
C-39 Roofing Contractor
Installs and repairs roofing and waterproofing materials that keep water out of structures.
Trade exam: yes · Free practice, study guide, cheat sheet · 5,568 active licenses (CSLB Data Portal, read November 7, 2026)
C-42 Sanitation System Contractor
Installs septic tanks, cesspools, storm drains and other sewage and drainage structures and their piping.
Trade exam: yes · No PrepPass material yet · 953 active licenses (CSLB Data Portal, read November 7, 2026)
C-43 Sheet Metal Contractor
Fabricates and installs sheet metal items such as flashing, gutters, ductwork, metal flues and metal roofing.
Trade exam: yes · No PrepPass material yet · 1,267 active licenses (CSLB Data Portal, read November 7, 2026)
C-45 Sign Contractor
Fabricates and installs electrical and non-electrical signs, including the sign wiring.
Trade exam: yes · No PrepPass material yet · 858 active licenses (CSLB Data Portal, read November 7, 2026)
C-46 Solar Contractor
Installs and services thermal and photovoltaic solar energy systems and only the other trade work needed for that.
Trade exam: yes · Free practice, study guide, cheat sheet · 1,136 active licenses (CSLB Data Portal, read November 7, 2026)
C-47 General Manufactured Housing Contractor
Installs, repairs or prepares manufactured homes and mobilehomes for moving, including foundations, accessory structures and single-site utility hookups.
Trade exam: yes · No PrepPass material yet · 445 active licenses (CSLB Data Portal, read November 7, 2026)
C-49 Tree and Palm Contractor
Plants, prunes, guys and removes trees and palms, including stump grinding.
Trade exam: yes · No PrepPass material yet · 636 active licenses (CSLB Data Portal, read November 7, 2026)
C-50 Reinforcing Steel Contractor
Fabricates, places and ties rebar and steel mesh used to reinforce concrete.
Trade exam: yes · No PrepPass material yet · 248 active licenses (CSLB Data Portal, read November 7, 2026)
C-51 Structural Steel Contractor
Fabricates and erects structural steel members, including the welding, rigging and metal roofing needed.
Trade exam: yes · No PrepPass material yet · 1,506 active licenses (CSLB Data Portal, read November 7, 2026)
C-53 Swimming Pool Contractor
Builds swimming pools, spas and hot tubs, including pool solar heating.
Trade exam: yes · No PrepPass material yet · 2,842 active licenses (CSLB Data Portal, read November 7, 2026)
C-54 Ceramic and Mosaic Tile Contractor
Prepares surfaces and installs ceramic, mosaic, quarry, glass and stone tile and stone slabs inside buildings.
Trade exam: yes · Free practice, study guide, cheat sheet · 6,058 active licenses (CSLB Data Portal, read November 7, 2026)
C-55 Water Conditioning Contractor
Installs water conditioning equipment with only the piping needed to connect it to the water supply.
Trade exam: yes · No PrepPass material yet · 299 active licenses (CSLB Data Portal, read November 7, 2026)
C-57 Well Drilling Contractor
Drills, cases and repairs water wells and pumps to supply clean water.
Trade exam: yes · No PrepPass material yet · 710 active licenses (CSLB Data Portal, read November 7, 2026)
C-60 Welding Contractor
Joins and fabricates metals using gas or electric welding processes.
Trade exam: yes · No PrepPass material yet · 1,066 active licenses (CSLB Data Portal, read November 7, 2026)
Limited specialty (C-61)
A single umbrella class for narrow trades. It has no trade exam.
C-61 Limited Specialty has no trade exam: CSLB's Examination Study Guides page lists it as "No study guide available (No trade exam required)", so a C-61 applicant needs only the Law and Business exam. CSLB endorses each C-61 license with a D subcategory (for example D-12 Synthetic Products or D-64 Non-specialized).
C-61 Limited Specialty
Umbrella specialty class for narrow trades not covered by another C class; the license is endorsed with the specific D-subcategory scope.
Trade exam: no
Certifications
ASB and HAZ are added to an existing license and have their own CSLB exams.
ASB Asbestos Certification
Certification added to an existing license so the qualifier can do asbestos-related work of 100 sq ft or more within the trades the license already covers.
Certification exam · No PrepPass material yet · 775 active licenses (CSLB Data Portal, read November 7, 2026)
HAZ Hazardous Substance Removal Certification
Certification required to do hazardous-substance removal or remedial digging at listed sites and to install or remove underground storage tanks.
Certification exam · No PrepPass material yet · 1,780 active licenses (CSLB Data Portal, read November 7, 2026)