Guides / NAICS codes for small business government contracting

NAICS codes for small business government contracting

Last reviewed November 2, 2026 · Educational content, not legal advice

In federal contracting, a NAICS code does two jobs: it describes what is being bought, and—through SBA’s size standards—it decides who counts as a small business for that purchase. Getting this right affects which set-asides you can bid on and which notices you should be watching.

What a NAICS code is

The North American Industry Classification System (NAICS) classifies businesses by the products or services they supply. The official code list and search are published by the U.S. Census Bureau (census.gov/naics). NAICS is revised every five years, and FAR Part 19 notes that new codes cannot be used in federal contracting until SBA publishes matching size standards (FAR Overhaul 19.103(a)).

How NAICS codes connect to “small business”

SBA assigns a size standard to each NAICS code, expressed either as a number of employees or as average annual receipts. SBA summarizes the typical pattern—most manufacturers with 500 or fewer employees and most non-manufacturers with average annual receipts under $7.5 million qualify as small—but stresses there are many exceptions by industry (SBA). The authoritative list is the size standards table at 13 CFR 121.201 (eCFR; also SBA’s table and Size Standards Tool).

Who picks the NAICS code on a solicitation

• The contracting officer assigns one NAICS code and its size standard to each solicitation, choosing the industry that best describes the principal purpose of the supplies or services being acquired (FAR Overhaul 19.103(b)).
• The size standard in effect on the date the solicitation is issued applies (19.103(c)).
• SBA determines your size—including affiliates—as of the date you represent that you are small as part of your initial offer that includes price (19.103(a)(3)).
• To be eligible as a small business you represent in good faith that you meet the size standard for the solicitation’s NAICS code (19.201-1). Another offeror can protest that representation, and SBA’s determination is binding on the contracting officer.

Choosing NAICS codes for your SAM.gov profile

SBA notes that a business generally has a primary NAICS code but can list several if it sells several kinds of products or services (SBA). A practical approach:

1. Start from what you actually do. Search the Census NAICS list by keyword and read the full definitions, including what is excluded.
2. Check what agencies used for similar work. Past award records on USAspending.gov show the NAICS codes buyers actually assigned. On OppBeacon you can also browse open notices by code—for example 541511 Custom Computer Programming, 541330 Engineering Services or 236220 Commercial Building Construction—to see which descriptions land under which code.
3. Check your size under each code with SBA’s Size Standards Tool. A code where you are not small still matters for full-and-open work, but not for small business set-asides.
4. Watch related codes. Similar work is often split across neighboring codes in the same 4-digit industry group (e.g., 541511, 541512, 541519).

If you think the NAICS code is wrong: the 10-day appeal

A contracting officer’s NAICS designation is final unless appealed. Anyone adversely affected may appeal to SBA’s Office of Hearings and Appeals, and the appeal must be filed within 10 calendar days after the solicitation—or an amendment affecting the NAICS code—is issued; late appeals are dismissed (FAR Overhaul 19.103(d)). If you plan to appeal, act immediately.

NAICS and WOSB set-asides

Women-owned small business (WOSB) and EDWOSB set-asides can only be used in NAICS codes where SBA has found WOSBs underrepresented or substantially underrepresented (19.107-2). SBA publishes the eligible list (SBA). More in our set-aside guide.

FAQ

Sources

1. U.S. Census Bureau — North American Industry Classification System
2. SBA — Get started with contracting (UEI, NAICS, size standards, market research)
3. SBA — Table of small business size standards
4. SBA — Size Standards Tool
5. eCFR — 13 CFR 121.201, size standards by NAICS industry
6. Acquisition.gov — FAR Overhaul Part 19, Small Business
7. SBA — NAICS codes eligible for the WOSB Federal Contract program
8. USAspending.gov — federal award data

More guides

• How to find federal contract opportunities on SAM.gov
• Sources sought vs RFI vs RFP vs RFQ (and IFB): what each SAM.gov notice means
• Federal set-aside types: small business, 8(a), HUBZone, SDVOSB and WOSB
• How to respond to a sources sought notice

OppBeacon is an independent software product. It is not affiliated with, endorsed by, or acting on behalf of the U.S. government or SAM.gov. We do not submit bids, register businesses, file government paperwork, or provide consulting, IT, or development services. Data comes from publicly available SAM.gov records.