830 Classification Policy
(b) Contractors licensed in one classification shall be prohibited from contracting in the field of any other classification unless they are also licensed in that classification or are permitted to do so by Section 831.

7117.6 Contracting out of Classification

Acting in the capacity of a contractor in a classification other than that currently held by the licensee constitutes a cause for disciplinary action.

California Contractors License Classifications

A General Engineering Contractor
B General Building Contractor
C-2 Insulation and Acoustical Contractor
C-4 Boiler, Hot Water Heating, Steam Fitting Contractor
C-5 Carpentry Contractor
C-6 Cabinet and Millwork Contractors
C-7 Low Voltage System Contractor
C-8 Concrete Contractor
C-9 Drywall Contractor
C-10 Electrical Contractor
C-11 Elevator Contractor
C-12 Earthwork and Paving Contractors
C-13 Fencing Contractor
C-14 Metal Roofing Contractor
C-15 Flooring & Floor Covering Contractor
C-16 Fire Protection Contractor
C-17 Glazing Contractor
C-20 Warm Air Heating, Ventilating & Air
Conditioning Contractor
C-21 Building Moving/Demolition Contractor
C-23 Ornamental Metals Contractor
C-26 Lathing Contractor
C-27 Landscaping Contractor
C-29 Masonry Contractor
C-32 Parking and Highway Improvement
Contractor
C-33 Painting and Decorating Contractors
C-34 Pipeline Contractor
C-35 Plastering Contractor
C-36 Plumbing Contractor
C-38 Refrigeration Contractor
C-39 Roofing Contractor
C-42 Sanitation System Contractor
C-43 Sheet Metal Contractor
C-45 Electrical Sign Contractor
C-46 Solar Contractor
C-47 General Manufactured Housing
Contractor
C-50 Reinforcing Steel Contractor
C-51 Structural Steel Contractor
C-53 Swimming Pool Contractor
C-54 Tile Contractors - Ceramic & Mosaic
C-55 Water Conditioning Contractor
C-57 Water Drilling Contractor
C-60 Welding Contractor
C-61 Limited Specialty Contractor
C-61 (Limited Specialty)
(a) Limited specialty is a specialty contractor classification limited to a field and scope of operations of specialty contracting for which an applicant is qualified other than any of the specialty contractor classifications listed and defined in this article.'
(b) An applicant classified and licensed in the classification Limited Specialty shall confine activities as a contractor to that field or fields and scope of operations set forth in the application and accepted by the Registrar or to that permitted by Section 831.
(c) Upon issuance of a C-61 license, the Registrar shall endorse upon the face of the original license certificate the field and scope of operations in which the licensee has demonstrated qualifications.
(d) A specialty contractor, other than a C-61 contractor, may perform work within the field and scope of the operations of Classification C-61, provided the work is consistent with established usage and procedure in the construction industry and is related to the specialty contractor's classification.

(D License - Is a Subclassification of C-61)

D-3 Awnings
D-4 Drywall Contractor
D-6 Concrete Related Services
D-9 Drilling, Blasting, & Oil Field Work
D-10 Elevated Floors
D-12 Synthetic Products
D-16 Hardware, Locks & Safes
D-21 Machinery and Pumps
D-24 Metal Products
D-28 Doors, Gates & Activating Devices
D-29 Paperhanging
D-30 Pile Driving/Pressure Foundation Jacking/Gunite
D-31 Pole Installation & Maintenance
D-34 Prefabricated Products/Equipment
D-35 Pool Spa & Maintenance
D-38 Sand and Water Blasting
D-39 Scaffolding
D-41 Siding and Decking
D-42 Sign Installation
D-49 Tree Service
D-50 Suspended Ceilings
D-52 Window Coverings
D-53 Wood Tanks
D-56 Trenching
D-59 Hydroseed Spraying
D-62 Air and Water Balancing
D-63 Construction Clean Up
D-64 Non-specialized
D-65 Weatherization & Energy Conservation

(Note: Some "D" licenses have been discontinued; contact CSLB if you have questions)