Choosing the correct NAICS code is one of the highest-leverage decisions a construction or specialty contractor makes before pursuing federal work. It determines which solicitations you match, whether you qualify as a small business, and how contracting officers find you. This guide lists the NAICS codes construction and electrical contractors use most, explains the SBA size standards attached to each, and shows how your code connects to a GSA Schedule.
What is a NAICS code?
NAICS (North American Industry Classification System) is the standard the U.S. federal government uses to classify businesses by industry. Each code is six digits, and every federal solicitation is tagged with one. Your business can hold many NAICS codes, but you designate a primary code in SAM.gov that best represents your core work. For a full primer, see our complete guide to NAICS codes.
Key NAICS codes for construction and contractors
| NAICS Code | Industry | SBA Size Standard |
|---|---|---|
| 236220 | Commercial & Institutional Building Construction | $45.0M |
| 236118 | Residential Remodelers | $45.0M |
| 237310 | Highway, Street & Bridge Construction | $45.0M |
| 238210 | Electrical Contractors & Other Wiring Installation | $19.0M |
| 238220 | Plumbing, Heating & Air-Conditioning Contractors | $19.0M |
| 238160 | Roofing Contractors | $19.0M |
| 238990 | All Other Specialty Trade Contractors | $19.0M |
Size standards change periodically; always confirm the current figure in the SBA Size Standards table before certifying.
What is the NAICS code for a general contractor?
Most general contractors use 236220 (Commercial & Institutional Building Construction) for non-residential work or 236118 for residential remodeling. General building construction codes carry a revenue-based small business size standard of $45.0 million averaged over three years.
What is the NAICS code for an electrical contractor?
Electrical contractors fall under 238210 — Electrical Contractors and Other Wiring Installation Contractors, with a $19.0 million size standard. This covers wiring, electrical equipment installation, and low-voltage systems work.
How do NAICS codes and SBA size standards work together?
Each NAICS code has its own SBA size standard, expressed either as average annual receipts (dollars) or number of employees. You are considered a small business for a given opportunity only if you fall under the size standard tied to that solicitation’s NAICS code. That is why the same company can be “small” for one contract and “other than small” for another.
Where do you set your NAICS code?
You declare your NAICS codes during SAM.gov registration. Choose every code that legitimately reflects your capabilities, then mark the most representative one as primary. Contracting officers and prime contractors filter potential vendors by these codes, so accuracy directly affects your visibility.
From NAICS code to GSA Schedule
Your NAICS codes map to the Large Categories and Special Item Numbers (SINs) on the GSA Multiple Award Schedule. If you plan to sell to federal buyers repeatedly, a GSA MAS contract turns one-off bids into a long-term sales channel. Confused about which codes and SINs fit your business? Book a free discovery call and we will map them for you.
Frequently asked questions
Can a business have more than one NAICS code?
Yes. There is no limit to how many NAICS codes you can list in SAM.gov. You designate one primary code, but you can be eligible under any code that matches your work.
What is the NAICS code list for construction?
Construction codes live in NAICS Sectors 23. The most common federal ones are the 236xxx (building construction), 237xxx (heavy and civil engineering), and 238xxx (specialty trade contractor) series.
Does my NAICS code affect whether I qualify as a small business?
Absolutely. Each code carries its own SBA size standard, so your small-business status is evaluated per NAICS code on each solicitation.
Reviewed by the GSA Focus team — specialists in helping contractors win and manage GSA Schedule contracts.
