NCCI Workers’ Comp Class Codes for Contractors: The Complete Guide

If you’re a contractor operating outside of California, your workers’ compensation class code is probably assigned through the NCCI system. The National Council on Compensation Insurance (NCCI) maintains the classification codes used in 38 states, plus the District of Columbia. A handful of other states run their own rating bureaus (like California’s WCIRB, New York’s NYCIRB, and state-specific bureaus in Delaware, Massachusetts, Michigan, Minnesota, New Jersey, North Dakota, Ohio, Pennsylvania, Washington, Wisconsin, and Wyoming), but many of those still base their codes on the NCCI framework.

Your class code is one of the biggest factors in your workers’ comp premium. If the wrong code lands on your policy, you could end up overpaying by thousands, or you could face a painful audit adjustment when the insurer figures out the mistake.

This guide covers the most common NCCI class codes assigned to contractors, which trades they apply to, and what to watch for. For a broader overview of construction insurance coverage types, see our complete guide.

How NCCI class codes work

Every employee on a workers’ comp policy gets assigned a class code based on the work they actually perform. Not what your business license says. Not what your company name implies. The actual, physical work each person does on the job.

Each class code carries a rate expressed as a cost per $100 of payroll. High-risk trades like roofing, tree service, and structural steel carry much higher rates than office work. A roofer might cost $15+ per $100 of payroll, while clerical staff will run under $1 per $100. For a detailed breakdown of insurance costs by trade, see our cost guide.

NCCI maintains roughly 700 class codes across all industries, but contractors typically fall into a few dozen categories. The codes below are the ones you’re most likely to encounter.

A few things to keep in mind

Your insurer assigns the class code at the time the policy is written, but it gets verified at audit. If the code on your policy doesn’t match the actual work performed, the auditor will reclassify your payroll and adjust your premium accordingly. That can go in your favor if you were overclassified, or it can result in an additional premium bill if you were under.

If your company performs multiple types of work, employees may be split across different class codes. A plumbing company that also does HVAC installation might have some employees under the plumbing code and others under the HVAC code. Payroll records need to support the split.

Subcontractor management matters too. If you use subcontractors and they don’t carry their own workers’ comp insurance, their payroll can end up on your policy at whatever class code matches their work.

Office and general codes

8810 – Clerical Office Employees

This code covers employees who work exclusively in an office performing administrative duties like data entry, filing, answering phones, bookkeeping, and general office management. Receptionists, office managers, bookkeepers, and administrative assistants in construction companies typically fall here.

The key word is “exclusively.” If your office person occasionally visits job sites, drops off materials, or does any manual work, they may not qualify for 8810. This is one of the cheapest class codes available, so keeping your office staff properly separated from field operations can save real money.

5606 – Contractor, Project Management Only

This covers construction executives, project managers, and superintendents who manage projects but do not perform hands-on work. The person classified here should be supervising through foremen only, not picking up a hammer or running equipment.

General contractors who subcontract the majority of their work and spend their time coordinating subs, managing timelines, and overseeing from a distance use this code. If the GC occasionally self-performs work, the payroll for that time gets assigned to the trade code for the work performed.

8227 – Construction Yard Operations

For permanent construction yards where crews recondition forms, store equipment, and manage supplies. Concrete form rental operations also fall here. This code is separate from the field work codes and covers the yard operations specifically.

Carpentry

5645 – Carpentry, Residential Construction

Covers carpenters building one- and two-family homes up to three stories. This includes framing, decking, siding, trim work, and installing cabinets, windows, and doors. Residential builders and carpenter insurance clients working on single-family homes are the most common users.

This is one of the most widely used class codes in residential construction. If you’re a general contractor self-performing carpentry on houses, this is likely your primary code.

5403 – Carpentry, Commercial & Large Buildings

For carpenters working on commercial projects or residential buildings over three stories. All carpentry work on office buildings, retail spaces, apartment complexes, and mixed-use buildings falls here. The rate is typically higher than residential carpentry because commercial projects tend to involve more complex structures and greater heights.

5651 – Carpentry, Multi-Family Dwellings

Covers carpentry work on apartments, condos, and townhomes up to three stories. This includes framing, siding, trim, and cabinet installation. This code is used in a limited number of states (primarily Florida and Virginia), so check whether your state applies it or rolls multi-family work into another carpentry code.

5437 – Carpentry, Cabinet/Trim Installation

For finish carpentry contractors installing cabinets, interior trim, countertops (except stone), and hardwood floors. Kitchen remodeling specialists, cabinet installers, and finish carpenters doing interior millwork use this code. This carries a lower rate than rough carpentry because the work involves less structural risk.

This code also applies to wood floor installation, sanding, and scraping. If your crew installs hardwood flooring by cutting, sanding, drilling, and attaching with nails, pegs, or screws, this is the code that applies.

2802 – Carpentry, Shop Only

For woodworking shops manufacturing doors, windows, trusses, stairs, and millwork with no on-site installation work. Cabinet makers, truss manufacturers, and millwork shops that only work in their facility use this code. The rate is significantly lower than field carpentry codes because the controlled shop environment reduces injury risk.

Concrete work

5221 – Concrete, Flatwork

Covers concrete contractors pouring concrete floors, driveways, sidewalks, and patios. Decorative concrete and paver installation also fall here. If your crew’s primary work is slabs on grade, walkways, and driveways, this is your code.

5215 – Concrete, Residential

For concrete work on one- and two-family homes including foundations, driveways, and patios. Not for monolithic concrete homes. Residential concrete contractors pouring basement walls, garage slabs, and residential driveways are common users.

5213 – Concrete Construction

The broader concrete construction code covering foundations, walls, and commercial buildings. Forming, pouring, and finishing structural concrete all fall here. Commercial concrete contractors, foundation specialists, and contractors building concrete structures use this code. This is the go-to classification for concrete work that doesn’t fit neatly into the residential or flatwork categories.

5225 – Reinforcing Steel Installation

Ironworkers installing rebar, wire mesh, post-tension cables, and other reinforcing steel in concrete structures are classified here. Tying rebar for foundations, walls, columns, and elevated slabs all falls under this code. Commercial concrete reinforcement subcontractors are the primary users.

5223 – Swimming Pool Construction

Covers contractors constructing, installing, or repairing swimming pools (non-iron/steel). This includes concrete pools, fiberglass pools, vinyl liner pools, and related appurtenances. Pool contractors and concrete pool builders use this code. Excavation work gets classified separately under 6217, and pool maintenance falls under 9014.

Electrical

5190 – Electrical Wiring, Buildings

Covers electricians doing interior wiring, fixture installation, and electrical repairs in buildings. Residential and commercial wiring, panel upgrades, and fixture installation all fall here. This is the standard electrical contractor class code and one of the most commonly used in the trades.

7605 – Alarm System Installation

For contractors installing burglar alarms, fire alarms, security cameras, and security systems. Low-voltage contractors doing residential and commercial security work use this code. The rate is generally lower than the standard electrical code because low-voltage work carries less risk than line-voltage electrical.

6325 – Conduit Construction

Covers contractors installing underground conduit for electrical cables and wires, including trenching and conduit placement. Electrical contractors doing underground utility work and cable installation use this code. The rate reflects the added risk of trenching and underground work.

5195 – Communications Cabling

Low-voltage technicians installing data cables, phone systems, fiber optic lines, network cabling, and structured cabling fall here. IT contractors, telecom installers, and audio/visual installation firms commonly use this code. The rate is lower than standard electrical work because low-voltage cabling is inherently less dangerous.

Plumbing

5183 – Plumbing & Sprinkler Installation

Covers plumbers installing water supply lines, drain/waste/vent piping, fixtures, water heaters, and underground lawn sprinklers. Residential and commercial plumbing contractors, irrigation system installers, and service plumbers all fall here. This is one of the most common class codes in the mechanical trades.

5185 – Fire Sprinkler Installation

Covers sprinkler fitters installing fire suppression systems. This is separate from general plumbing because fire protection work involves its own skill set, licensing, and risk profile. Both residential and commercial fire sprinkler contractors use this code.

HVAC and mechanical

5537 – HVAC Installation & Service

Covers HVAC contractors installing and servicing heating, ventilation, air conditioning, and refrigeration systems. Residential furnace replacements, commercial rooftop unit installations, ductless mini-split setups, and general HVAC service work all fall here.

This is a broad code that covers both installation and service. Some states may break this down further, but in most NCCI states, 5537 is the primary HVAC classification.

5535 – Sheet Metal Installation

For contractors installing metal ceilings, wall coverings, metal awnings, and sheet metal work. HVAC duct installers, metal siding contractors, and architectural metal installers on commercial buildings use this code.

Roofing

5551 – Roofing, All Types

Covers roofing contractors installing shingles, metal roofing, flat roofing membranes, and performing repairs. All roofing materials and methods fall here, from asphalt shingles on houses to single-ply membranes on commercial buildings.

Roofing is consistently one of the most expensive class codes because of the fall hazard inherent in the work. Expect rates significantly higher than most other construction trades. If you operate a roofing company, this code is likely the single biggest driver of your workers’ comp premium.

Painting and coatings

5474 – Painting, All Types

Covers painting contractors working on buildings, metal tanks, fire escapes, and interiors. Includes brush and spray application and waterproofing. Residential and commercial painters use this code, excluding bridges or structures over two stories (which fall under a separate high-structure code).

5037 – Painting, High Structures

For painters working on metal structures over two stories, bridges, water towers, and similar high-risk environments. Industrial painting contractors, bridge painters, and tower painting specialists use this code. The rate is substantially higher than standard painting due to the fall exposure.

Drywall and plaster

5445 – Wallboard Installation

Covers drywall contractors installing sheetrock, taping, and finishing. Metal stud framing is included. Commercial interior contractors and drywall companies working on walls and ceilings use this code.

5480 – Plastering, Interior

For plasterers doing interior plastering, drywall finishing, and acoustic ceilings. Includes interior waterproofing. Plastering contractors and drywall finishers on commercial and residential interiors use this code.

Flooring and tile

5348 – Tile & Stone Installation

Covers contractors installing ceramic tile, marble, granite, and natural stone on floors, walls, showers, countertops, and backsplashes. Bathroom remodelers, tile contractors, and custom stone installation companies use this code.

5478 – Floor Covering Installation

For contractors installing carpet, vinyl, and laminate flooring. Does not include hardwood (that falls under 5437) or tile (which has its own code under 5348). Flooring stores, carpet installers, and contractors specializing in resilient flooring use this code.

Masonry

5022 – Masonry Construction

Covers masonry contractors building with brick, block, and stone. Includes fireplaces, chimneys, stucco, and exterior plastering. Brick masons, block layers, and stone contractors on commercial and residential projects use this code.

Structural steel and iron

5040 – Steel Erection, Structural

Ironworkers erecting structural steel frames, columns, beams, and girders for buildings are classified here. Steel erection contractors on commercial construction, warehouse frames, and multi-story steel structures are the primary users.

This is one of the highest-rated class codes due to the significant fall and crush hazards. If you’re in the steel erection business, expect your workers’ comp costs to be among the highest in construction.

5057 – Iron/Steel Erection NOC

This covers miscellaneous iron and steel work that isn’t structural framing. Ornamental iron railings, commercial stair systems, metal fencing panels, and non-structural metal fabrication fall here. The rate is lower than structural steel erection because the work generally involves less height and lighter members.

Excavation, grading, and site work

6217 – Excavation & Grading

Covers equipment operators doing excavation, trenching, grading, and earthmoving for construction projects. Site prep contractors, excavation companies, and utility trenching contractors use this code.

5506 – Street/Road Construction, Paving

For contractors paving roads, parking lots, driveways, and airport runways. Includes asphalt and concrete paving, resurfacing, and seal coating. Paving companies and road construction contractors use this code. Excavation and grading are classified separately.

Underground utilities

6306 – Sewer Construction, All Operations

Covers contractors building sewer mains, storm sewers, and underground sewer systems. Includes excavation, pipe laying, manholes, and connections. Municipal sewer contractors and utility construction companies use this code.

6319 – Water/Gas Main Construction

For utility contractors installing water mains, gas lines, and connections. Includes trenching and pipe laying. Underground utility contractors and municipal contractors doing water and gas line work use this code.

6229 – Septic Tank, Installation & Service

Covers contractors installing septic tanks, drainage systems, and irrigation systems. Includes excavation, tank placement, drain field installation, and system connections. Septic installers and drainage contractors use this code.

9402 – Sewer Cleaning, Service & Maintenance

For companies cleaning and maintaining sewer lines, storm drains, and catch basins. Includes jetting, rodding, video inspection, and debris removal. Drain cleaning services and septic pumping companies use this code.

Landscaping, tree service, and pest control

0042 – Landscape Gardening

Covers landscaping contractors doing lawn care, planting, garden design, irrigation installation, and hardscape work. Full-service landscape contractors, irrigation specialists, and landscape maintenance companies all fall here. This is a broad code covering everything from weekly mowing to full backyard transformations.

9102 – Lawn Maintenance Services

For lawn care companies focused on mowing, trimming, weed control, and lawn treatments. Ground-level tree work only. If your business is primarily routine lawn maintenance rather than full landscape construction, this code may apply.

0106 – Tree Service

Tree trimming, pruning, removal, stump grinding, and emergency storm damage work are all classified here. Arborists, tree care companies, and land clearing services focused on tree removal use this code.

Tree service is one of the most expensive class codes in workers’ comp due to the extreme fall hazard from climbing and the danger of working with chainsaws at height. Expect rates comparable to or higher than roofing.

5650 – Termite Control Work

Pest control operators doing termite inspections, treatment, fumigation, and wood damage repair are classified here. Structural pest control companies and termite repair contractors use this code.

9031 – Pest Control

General pest extermination services (excluding termite work) fall here. Monthly pest spraying, rodent control, bed bug treatment, and general pest management are all included.

Specialty trades

5102 – Door & Window Installation

Covers contractors installing residential and commercial doors and windows. Aluminum, vinyl, wood, fiberglass, storm shutters, and shower doors are all included. Window replacement companies and door installation specialists use this code.

3724 – Door Installation, Overhead

For contractors installing overhead and garage doors, commercial equipment, and machinery. Includes electric door operators and loading dock equipment. Garage door companies and commercial equipment installation contractors use this code.

5146 – Furniture Installation, Portable

Covers contractors installing office furniture, cubicles, modular workstations, and metal partitions. Office furniture dealers and commercial furniture installers use this code.

9521 – Display & Sign Installation

Covers contractors installing advertising displays, signs, and window displays from floor level. Sign companies, display installers, and visual merchandising contractors use this code.

5479 – Insulation Work

Covers contractors installing thermal and acoustic insulation in walls, attics, and buildings. Fiberglass batts, blown-in cellulose, spray foam, rigid board, and pipe insulation all fall here. Insulation contractors and energy efficiency retrofit specialists use this code.

5160 – Elevator Installation

Elevator mechanics installing, repairing, modernizing, and maintaining elevators, escalators, dumbwaiters, and moving walkways. Elevator contractors and elevator service companies are the primary users.

6400 – Fence Installation

Covers installation of wood, vinyl, metal, and chain link fences. Residential and commercial fence installers are the primary users. Note that brick, stone, or concrete block fences get classified under the masonry code, not here.

3365 – Welding or Cutting

Covers welding and cutting operations not otherwise classified, including both shop and outside work. Mobile welding services, metal fabrication shops, repair welding operations, and custom fabrication welders use this code. If welding is done as part of a larger construction project (like structural steel erection), it gets classified under the construction code for that work instead.

3179 – Electrical Equipment Manufacturing

For manufacturers making electrical fixtures, appliances, and equipment. Shop work only, no installation. Companies manufacturing light fixtures, electrical components, and small appliances in factory settings use this code.

9519 – Appliance Service & Repair

Covers technicians servicing household and commercial appliances including installation and repair. Appliance repair companies and service techs working on refrigerators, washers, dryers, and dishwashers use this code.

5191 – Office Machine Service

For technicians servicing computers, printers, copiers, and office equipment. IT service companies, computer repair shops, and office equipment dealers doing service calls use this code.

Cleaning services

9014 – Janitorial Services

Commercial cleaning crews, office cleaners, and building maintenance cleaning staff fall here. Post-construction cleanup crews and commercial cleaning contractors are common users. This code also covers power or pressure washing at ground level using portable water or steam cleaning systems.

9170 – Window Cleaning, Above Ground

For window cleaning contractors working above ground level using ladders, scaffolds, or lifts. Commercial window cleaning companies servicing office buildings and high-rises use this code. The rate is higher than standard janitorial work because of the fall exposure.

0917 – Residential Cleaning Services

House cleaning services working inside private homes, including regular cleaning, deep cleaning, and move-in/move-out cleaning. Residential cleaning companies and maid services use this code.

5610 – Cleaner, Debris Removal

Covers cleanup crews removing construction debris after project completion. Does not include detailed cleaning for occupancy. Construction cleanup contractors and debris removal services at job sites use this code.

2585 – Carpet/Upholstery Cleaning

For carpet cleaning services working in homes and businesses. Includes rug and upholstery cleaning in shop or on-site. Carpet cleaning companies and restoration services doing water damage cleanup use this code.

Swimming pool services

9014 – Swimming Pool Cleaning

Covers pool cleaning and maintenance by contract. Routine pool cleaning, chemical balancing, equipment maintenance, and related pool service work fall here. Pool service route companies and maintenance contractors use this code. Pool construction is classified separately under 5223.

NCCI vs. state-specific systems

While NCCI codes are the standard in most of the country, it’s worth knowing that several states maintain their own classification systems. California uses the WCIRB, New York uses the NYCIRB, and states like Delaware, Massachusetts, Michigan, Minnesota, New Jersey, North Dakota, Ohio, Pennsylvania, Washington, Wisconsin, and Wyoming each have their own bureaus.

If you operate in multiple states, you may have different class codes on your policy for employees in different locations. A framing carpenter in Texas (NCCI state) might carry a different code than the same carpenter working in California (WCIRB state). Your agent should make sure each state’s classification is accurate.

Tips for getting your class codes right

Review your classifications every year. Employee roles change, and so do NCCI rules. What was accurate two years ago might not be today.

Keep payroll records separated by class code. If you have employees doing different types of work, your payroll needs to be clearly divided. If you can’t prove the split, all payroll may get assigned to the highest-rated code.

Watch your subcontractor certificates. If you use subs and their insurance lapses, their payroll can end up on your experience mod. Stay on top of certificate tracking year-round. If you’re a sole proprietor who needs a policy just to satisfy a GC’s requirements, read our guide on workers’ comp ghost policies to understand your options.

Ask about classification before binding. If you’re shopping for coverage and a quote seems unusually high or low, ask the agent what class code they used. An incorrect code can lead to a big audit adjustment.

Understand the governing class code rule. NCCI assigns a “governing class” to each policy based on the classification that carries the largest amount of payroll. Your governing class affects your experience modification factor calculation, so getting the payroll split right matters beyond just the rate on each code.

Need help figuring out your class code?

If you’re a contractor and aren’t sure which workers’ comp class code applies to your business, we can help. At ContractorNerd, we work with contractors every day and know the classification system inside and out. Get a quote and we’ll make sure you’re properly classified from the start, so there are no surprises at audit time.

Class code descriptions in this article are based on the current NCCI classification system. Rules and interpretations can vary by state. Always verify your classification with your insurance agent or directly with NCCI.