NAICS codes are the classification system the federal government uses to categorize business activities. For federal contractors, they have three functions that directly affect revenue: they determine your small business size standard, they determine which contracts you are eligible to bid on, and they determine which opportunities appear in your opportunity feed when using platforms like SAM.gov or VetBid's Scout.

Choosing the wrong NAICS codes, or choosing too few, is a silent revenue leak. Firms that have not reviewed and optimized their NAICS codes are almost certainly missing eligible opportunities that would match their capabilities.

What NAICS codes are

The North American Industry Classification System is a six-digit classification system developed jointly by the U.S., Canada, and Mexico to categorize business establishments by their primary economic activity. There are over 1,000 individual NAICS codes covering every commercial activity from agriculture to software development.

In federal contracting, every solicitation is assigned one or more NAICS codes that correspond to the primary work being procured. When a contracting officer posts a solicitation, they assign a NAICS code that determines which size standard governs the small business eligibility for that acquisition. Your firm's size relative to that NAICS code's size standard determines whether you can bid as a small business.

Primary vs. secondary NAICS codes

Your SAM.gov registration requires a primary NAICS code that best describes your firm's primary business activity. You may also add additional NAICS codes to reflect other capabilities your firm offers.

The primary NAICS code matters most for size standard determination at the certification level. When the SBA certifies you as a small business, they use your primary NAICS code's size standard as a starting point. However, at the contract level, what matters is the NAICS code assigned to the specific contract you are bidding on, not your primary code.

This means your primary NAICS code and the NAICS codes assigned to the contracts you pursue may differ. What matters is that you are a small business under the size standard for the specific contract you are bidding on.

Understanding size standards

The SBA publishes size standards for every NAICS code. Standards are expressed as either maximum average annual receipts (for most service industries) or maximum number of employees (for manufacturing and some other sectors).

For example, a firm with NAICS code 541512 (Computer Systems Design Services) must have average annual receipts of $34 million or less to qualify as small. A manufacturing firm under NAICS 332720 must have 500 employees or fewer. The standards vary significantly by NAICS code, and the SBA updates them periodically.

Size is calculated differently depending on the standard type. Revenue-based standards use average annual receipts over the most recent three completed fiscal years. Employee-based standards use the average number of employees, including part-time workers, over the most recent 12 months, or over the firm's existence if less than 12 months.

Affiliation rules and how they affect size

The SBA's affiliation rules can aggregate the revenues or employees of related businesses when calculating size. If you have ownership relationships, common management, or economic dependence relationships with other businesses, those firms' revenues or employees may count toward your size calculation.

Common affiliation triggers include: common ownership above 50 percent by the same individual or entity, common management by the same officer or director, contractual relationships that create economic dependence (where one firm relies on another for a large share of its revenue), and identity of interest between family members who each own businesses in the same industry.

Affiliation analysis is complex and fact-specific. If your business has any of these relationships, consult an attorney familiar with SBA size standards before self-certifying as small.

How to identify the right NAICS codes for your firm

Start by describing your firm's core services in plain language. What does your team actually do? Then search the SBA's NAICS code lookup tool at naics.com or through the Census Bureau's NAICS search for codes that correspond to those activities.

For professional services firms, the most commonly used NAICS codes in federal contracting include:

541512 (Computer Systems Design Services) for IT services, systems integration, and custom application development. 541330 (Engineering Services) for engineering consulting across multiple disciplines. 541611 (Administrative Management and General Management Consulting Services) for management consulting. 541690 (Other Scientific and Technical Consulting Services) for technical advisory services. 611430 (Professional and Management Development Training) for training and education services. 237000-series codes for construction and infrastructure. 336000-series codes for manufacturing and aerospace.

Do not restrict yourself to a single code. If your firm legitimately performs work in multiple categories, register all relevant codes. Every code you add expands the universe of set-aside opportunities that match your profile.

NAICS codes and set-aside eligibility

For SDVOSB set-aside purposes, eligibility is determined at the time of each contract offer based on the NAICS code assigned to that contract. If you are a small business under the applicable size standard, you are eligible to bid on set-asides in that NAICS category.

This means you can be a small business under some NAICS codes but not others simultaneously. A firm with $30 million in annual revenue is small under the 541512 ($34M) standard but not small under 541614 ($25.5M). Review the size standard for every NAICS code before bidding on contracts in that category.

NAICS codes and opportunity discovery

Your registered NAICS codes directly control which opportunities surface in your SAM.gov searches and in VetBid's Scout feed. Opportunities are tagged with the NAICS code of the primary work being procured, and that code is used to match opportunities to your profile.

If you have not reviewed your NAICS codes recently, do so now. Log into your SAM.gov registration and confirm that every NAICS code relevant to your current and target capabilities is listed. Then cross-reference the codes against recent SDVOSB set-aside awards in those codes using USASpending.gov to confirm that the government is actually buying in those categories.

Updating your NAICS codes

You can update your NAICS codes at any time through SAM.gov by editing your entity registration. Changes take effect when the update is processed, typically within 24 hours. You do not need to wait for your annual renewal to add new codes.

When you add new NAICS codes, also update your SBA certification record to reflect the expanded capability profile. And ensure that your capability statement and proposal materials accurately describe your work in the new categories. Adding a NAICS code you cannot substantively perform is a misrepresentation.