Water and Sewer Line and Related Structures Construction, Highway, Street, and Bridge Construction, Other Heavy and Civil Engineering Construction, Site Preparation Contractors

Electrical Contractors

Flooring Contractors

Industrial Building Construction

Site Preparation Contractors, All Other Specialty Trade Contractors, Transportation Equipment and Supplies (except Motor Vehicle) Merchant Wholesalers, Construction, Mining, and Forestry Machinery and Equipment Rental and Leasing

Residential Remodelers

Residential Remodelers, Masonry Contractors, Flooring Contractors, Tile and Terrazzo Contractors, Other Building Finishing Contractors

Plumbing, Heating, and Air-Conditioning Contractors

MANDATORY

Power and Communication Line and Related Structures Construction, Land Subdivision, Highway, Street, and Bridge Construction, Other Heavy and Civil Engineering Construction, Poured Concrete Foundation and Structure Contractors

Electrical Contractors

Electrical Contractors

Highway, Street, and Bridge Construction, All Other Specialty Trade Contractors, Landscape Architectural Services, Landscaping Services

Residential Remodelers, Framing Contractors, Roofing Contractors, Siding Contractors, Drywall and Insulation Contractors

Soil Preparation, Planting, and Cultivating, Masonry Contractors, Site Preparation Contractors, All Other Specialty Trade Contractors, Ornamental and Architectural Metal Work Manufacturing

Construction Sand and Gravel Mining, Water and Sewer Line and Related Structures Construction, Highway, Street, and Bridge Construction, Other Heavy and Civil Engineering Construction, Site Preparation Contractors

Residential Remodelers

New Single-Family Housing Construction (except Operative Builders)

Structural Steel and Precast Concrete Contractors, Other Foundation, Structure, and Building Exterior Contractors, All Other Specialty Trade Contractors

All Other Specialty Trade Contractors