North American Industry Classification System Code (NAICS Code)
A NAICS Code is a six-digit numeric code that the federal government uses to categorize businesses by their primary economic activity, determining which size standards apply, which set-aside programs a business qualifies for, and how agencies match opportunities to the right contractors.
What Is a NAICS Code?
A NAICS Code, short for North American Industry Classification System Code, is a six-digit numeric code that the federal government, U.S. Census Bureau, Statistics Canada, and Mexico's INEGI use to categorize businesses by their primary economic activity. NAICS replaced the older Standard Industrial Classification system in 1997.
The first two digits identify the broad sector (such as 23 for Construction or 54 for Professional, Scientific, and Technical Services), the third digit identifies the subsector, and the remaining digits drill down to industry group, industry, and U.S. industry. Federal acquisition activities use NAICS Codes to classify procurement opportunities, set size standards, and structure market research.
Every business that intends to sell to the federal government must register at least one primary NAICS Code in SAM.gov, along with any secondary codes that reflect additional capabilities.
Key Characteristics
NAICS Codes have several defining attributes. Each code is six digits long, with each successive digit narrowing the scope from broad sector down to U.S. industry.
A business holds one primary NAICS Code reflecting its main revenue source, plus optional secondary codes covering additional service lines. The system is jointly maintained by the United States, Canada, and Mexico, and is revised every five years (the 2022 revision is current; the next update lands in 2027).
Each NAICS Code maps to a specific small-business size standard set by the Small Business Administration, expressed either as a revenue cap or an employee count. NAICS Codes feed into SAM.gov, the Dynamic Small Business Search, federal solicitation portals, and most procurement notices.
How It Works in Government Contracting
Federal acquisition activities use NAICS Codes at three critical points in the contracting lifecycle. First, during market research, agencies use NAICS Codes to identify which businesses operate in a relevant industry, often by searching the Dynamic Small Business Search or pulling SAM.gov data filtered by code.
Second, when a solicitation is drafted, the contracting officer assigns a single NAICS Code to the procurement, which automatically attaches the corresponding size standard and determines which businesses qualify as small for that specific opportunity. Third, during evaluation, the assigned NAICS Code determines set-aside eligibility for programs like 8(a), HUBZone, WOSB, and SDVOSB.
A business with the wrong primary NAICS or missing secondary codes will not show up in the agency's market research, will not qualify for size-based set-asides on opportunities outside its registered codes, and may have to file a size protest or NAICS Code appeal to compete.
Real-World Example
A small IT services firm registers in SAM.gov with primary NAICS 541512 (Computer Systems Design Services), which carries a $34 million five-year average revenue size standard. The firm's actual revenue is $28 million, so it qualifies as small under that code.
The Department of Veterans Affairs releases a solicitation under NAICS 541330 (Engineering Services), which has a $25.5 million size standard. Because the firm's revenue exceeds $25.5 million under the engineering code, it cannot bid as a small business on the VA opportunity, even though it qualified as small under its primary code.
The firm files a NAICS Code appeal arguing that the work is predominantly IT services and should be classified under 541512. Outcomes like this are common and underline why NAICS selection at SAM.gov registration is one of the most consequential setup choices in GovCon.
Regulatory Framework
NAICS Codes are governed by FAR Part 19 and 13 CFR Part 121, which together establish how agencies assign NAICS Codes to solicitations and how the SBA sets corresponding size standards. FAR 19.102 requires the contracting officer to designate a single NAICS Code per solicitation and to use the SBA size standard that pairs with it.
Size standards themselves are published in 13 CFR section 121.201 and updated periodically. Businesses dissatisfied with a NAICS designation can file a NAICS Code appeal under 13 CFR section 121.1102 within 10 days of solicitation issuance.
Why It Matters for Contractors
NAICS Code selection has direct and lasting business consequences. The wrong primary code locks a firm out of opportunities it could otherwise win, because agency market research uses the firm's registered codes to build the bidder list.
Conversely, claiming too many secondary codes can dilute credibility and confuse evaluators looking for focused subject matter expertise. NAICS selection also drives long-term size status: as the firm grows, the revenue cap or employee threshold tied to its primary code determines exactly when it must graduate out of small-business set-asides.
Strategic contractors review their NAICS Codes annually, monitor SBA revisions, and align their proposal narratives to the code most likely to be used for target opportunities. Inattention here is the single most preventable reason small businesses miss federal work.
Common Misconceptions
A business is required to bid only under its primary NAICS Code.
In practice, a business can bid on any opportunity for which it registered as a secondary code, as long as it meets the size standard for that specific code.
NAICS Codes are interchangeable with Product Service Codes.
They are not. NAICS classifies the business; Product Service Codes (PSCs) classify what is being bought. Both can appear on a single solicitation.
NAICS Codes are permanent once set.
They are not. A business can update its NAICS profile in SAM.gov at any time, and the code on a specific solicitation can be challenged through a NAICS Code appeal.
Frequently Asked Questions
How many NAICS Codes can a business have?
A business can register one primary NAICS Code plus an unlimited number of secondary codes in SAM.gov. The primary code should reflect the highest source of revenue, while secondary codes capture additional service lines the firm can credibly perform. Most successful federal contractors carry between 5 and 15 secondary codes, chosen to align with target opportunity types.
How do I find the right NAICS Code for my business?
Search the Census Bureau's NAICS lookup tool, entering keywords that describe your primary service or product. Cross-reference your top revenue activity with the descriptions provided for each code. If multiple codes seem to apply, choose the one tied to your largest revenue line. You can validate the choice by reviewing SAM.gov registrations of similar firms.
What happens if the wrong NAICS Code is assigned to a solicitation?
File a NAICS Code appeal with the SBA Office of Hearings and Appeals within 10 calendar days of the solicitation's issuance, citing 13 CFR section 121.1102. The appeal must explain why a different NAICS Code more accurately describes the work. If the SBA agrees, the agency must amend the solicitation.
How often are NAICS Codes updated?
The NAICS system is revised on a five-year cycle by the U.S., Canada, and Mexico. The 2022 revision is current. The next scheduled revision is 2027. SBA size standards tied to NAICS Codes are reviewed on their own schedule and can change between NAICS revisions.
Does the NAICS Code on a contract determine which set-aside programs apply?
Yes. The NAICS Code assigned to a solicitation, paired with its SBA size standard, determines whether a business qualifies as small for that specific opportunity, and therefore whether 8(a), HUBZone, WOSB, SDVOSB, and small-business set-asides apply. The same firm can qualify as small under one code and large under another.
Related Government Contracting Topics
Size Standard: The revenue cap or employee count, set by the SBA, that pairs with each NAICS Code to determine whether a business qualifies as small for a given solicitation.
Small Business Administration (SBA): The federal agency that establishes and maintains NAICS-based size standards and adjudicates NAICS Code appeals and size protests.
Set-Aside: A procurement reserved for businesses meeting specific eligibility criteria tied to NAICS Code and size standard, including 8(a), HUBZone, WOSB, SDVOSB, and small-business set-asides.
8(a) Business Development Program: An SBA program for socially and economically disadvantaged small businesses, with eligibility evaluated against the NAICS Code of each opportunity.
HUBZone (Historically Underutilized Business Zone): An SBA set-aside program where qualifying small businesses in designated HUBZones receive preference on contracts within their registered NAICS Codes.
Women-Owned Small Business (WOSB): A set-aside category for small businesses at least 51% owned and controlled by women, with eligibility evaluated per opportunity NAICS Code.
Service-Disabled Veteran-Owned Small Business (SDVOSB): A set-aside program for businesses owned by service-disabled veterans, with size eligibility evaluated by NAICS Code.
System for Award Management (SAM.gov): The federal registration system where businesses declare their primary and secondary NAICS Codes and certify their size status.
Dynamic Small Business Search (DSBS): The SBA database agencies use to find small businesses by NAICS Code during market research.
Product Service Code (PSC): A separate code system that classifies what is being purchased, often paired with a NAICS Code on the same solicitation.
Federal Supply Class (FSC): An older product classification still used in some Department of Defense procurements alongside NAICS Codes.
Size Protest: A formal challenge to a competitor's small-business status for a specific procurement, evaluated against the assigned NAICS Code's size standard.
How LotusPetal AI Helps
LotusPetal AI's capture and proposal automation platform reads incoming solicitations, extracts the assigned NAICS Code and its corresponding size standard, and automatically flags whether your firm qualifies as small for that opportunity. Capture managers can configure NAICS-driven filters in opportunity intake so the team never spends time on solicitations outside its registered code set.