Top 10 NAICS Codes for Small Businesses New to Federal Contracting

When you register on SAM.gov, one of the most consequential decisions you'll make is selecting your NAICS codes. These 6-digit codes classify your business by industry and determine which federal contracts you can compete for. Choose the wrong codes — or too few — and you'll miss contracts you should be winning. Choose codes that don't accurately reflect your capabilities and you'll waste time pursuing work you're not set up to perform.

This guide covers the top 10 NAICS codes that small businesses new to federal contracting should be aware of, along with the key facts you need to evaluate whether they apply to your business.

What Are NAICS Codes and Why Do They Matter?

NAICS stands for North American Industry Classification System. The U.S. Census Bureau maintains these codes, which classify businesses by their primary economic activity. There are over 1,000 NAICS codes across all industries.

In federal contracting, NAICS codes matter for three reasons:

1. Contract eligibility — Each solicitation has a primary NAICS code. Generally, you need to be registered under that code to bid.

2. Small business size standards — The SBA defines "small business" differently for each NAICS code. For some codes, the standard is annual revenue (e.g., $19 million for many service industries). For others, it's number of employees (e.g., 500 employees for many manufacturing codes). Make sure you qualify under the codes you register.

3. Set-aside eligibility — Certifications like 8(a), HUBZone, WOSB, and SDVOSB are often tied to specific NAICS codes. Registering under the right codes ensures you can access set-aside opportunities.

The Top 10 NAICS Codes for New Federal Contractors

1. NAICS 541611 — Administrative Management and General Management Consulting Services *Size Standard: $19 million in annual revenue*

This is one of the most common NAICS codes in federal contracting. Management consultants help federal agencies improve processes, develop strategies, and manage organizational change. If you have business, management, or operations expertise, this code opens enormous opportunity. The federal government spends billions annually on management consulting across virtually every agency.

2. NAICS 541512 — Computer Systems Design Services *Size Standard: $34 million in annual revenue*

IT services represent one of the largest segments of federal procurement. This code covers custom computer programming, software design, and computer systems integration. With every federal agency modernizing IT infrastructure, demand for IT services contractors is consistently high. This code is particularly relevant for technology firms and software developers.

3. NAICS 561720 — Building Cleaning and Maintenance Services *Size Standard: $22 million in annual revenue*

Janitorial and facility cleaning services are among the most consistently procured services by federal agencies, military installations, and government buildings. Competition exists, but so does enormous volume. Many small businesses — including family-owned operations — have built substantial federal contracting revenue through building services contracts. This code is an excellent entry point for service businesses.

4. NAICS 236220 — Commercial and Institutional Building Construction *Size Standard: $45 million in average annual revenue over 3 years*

Federal construction is a massive market. Agencies are constantly building, renovating, and maintaining facilities. This code covers the construction of commercial and institutional buildings. If you're a licensed general contractor, this code can open doors to significant federal construction opportunities, particularly through the Army Corps of Engineers and General Services Administration.

5. NAICS 561110 — Office Administrative Services *Size Standard: $19 million in annual revenue*

Administrative support services include records management, data entry, clerical support, and general office administration. This code covers businesses that provide outsourced administrative functions to government agencies. It's a strong entry-level federal contracting NAICS code for businesses with administrative and office management capabilities.

6. NAICS 541620 — Environmental Consulting Services *Size Standard: $19 million in annual revenue*

Environmental consulting is a specialized and consistently funded federal contracting area. Agencies like the EPA, Department of Defense, and Department of Energy regularly need environmental assessments, remediation planning, compliance consulting, and sustainability services. If you have environmental science or engineering expertise, this code represents high-value opportunities.

7. NAICS 611430 — Professional and Management Development Training *Size Standard: $19 million in annual revenue*

Federal agencies invest heavily in employee training and development. This code covers businesses that provide professional development, leadership training, technical skills training, and management education. If you're a trainer, coach, or learning and development professional, federal training contracts can be highly lucrative.

8. NAICS 562111 — Solid Waste Collection *Size Standard: $41.5 million in annual revenue*

Waste management and collection services are needed at federal facilities nationwide. Military bases, government buildings, and federal lands all require waste collection services. This is a steady, recurring revenue source for businesses in the waste management sector.

9. NAICS 561210 — Facilities Support Services *Size Standard: $47 million in annual revenue*

Facilities management is one of the largest categories of federal procurement. This code covers comprehensive building operations and maintenance — covering everything from HVAC maintenance to grounds keeping, security, and facility operations. Federal agencies and military installations regularly award large, multi-year facilities management contracts.

10. NAICS 541690 — Other Scientific and Technical Consulting Services *Size Standard: $19 million in annual revenue*

This broader scientific and technical consulting code covers specialized advisory services that don't fit other categories. It's useful for businesses providing niche technical expertise — engineering analysis, scientific research support, technical writing, and similar specialized services.

How to Choose the Right Codes for Your Business

Here's the approach I recommend to every client:

*Step 1: Start with what you actually do* List every service or product your business provides. For each one, find the NAICS code that most accurately describes that activity. Don't stretch codes to cover activities you don't genuinely perform.

*Step 2: Check the size standards* For each code you're considering, verify that your business qualifies as small. Use the SBA's Size Standards Tool at sba.gov.

*Step 3: Research federal spending in that code* Use USASpending.gov to research how much federal money is spent in each NAICS code. Filter by contract awards in the past 1-3 years. This tells you whether real opportunity exists.

*Step 4: Identify your primary code* Your primary NAICS code is the one that best describes your core business. This is what SBA certifications and size determinations are based on. Choose thoughtfully.

*Step 5: Register all applicable secondary codes* You can register under multiple NAICS codes on SAM.gov. Register under every code that accurately describes your capabilities. More codes mean more opportunities to appear in contracting officer searches.

Common NAICS Code Mistakes

• Selecting codes based on where you want to work rather than what you actually do
• Forgetting to check size standards for each code
• Not updating codes when you add new capabilities
• Registering under too-broad codes that don't match specific solicitations
• Missing relevant codes because you didn't know they existed

Need Help with NAICS Code Selection?

NAICS code selection is one of the most important decisions in your SAM.gov registration. The wrong codes — or missing codes — directly impact which contract opportunities you can pursue.

The Contracting Preacher includes comprehensive NAICS code consultation as part of every SAM.gov registration engagement. We research federal spending in codes relevant to your business, help you identify the right primary code, and ensure your registration reflects all of your capabilities.

Schedule your free consultation to discuss your business and identify the NAICS codes that will open the most federal contracting doors for you.