NAICS Codes for Government Contracts: Complete Guide for 2026

NAICS codes (North American Industry Classification System) are 6-digit codes that classify every type of business activity in the United States, Canada, and Mexico. In government contracting, your NAICS codes determine which opportunities you can bid on, whether you qualify as a small business, and how agencies find your company.

Think of NAICS codes as the filing system for the entire economy. When a government agency needs IT consulting services, they search for contractors with NAICS code 541512. When they need janitorial services, they search for 561720. If your business is not registered with the right codes, agencies will not find you.

Why NAICS Codes Are Critical in Government Contracting:

1. Small Business Size Standards
Your primary NAICS code determines whether you qualify as a small business. Each NAICS code has its own size standard based on either annual revenue or number of employees:

• NAICS 541330 (Engineering Services): $25.5 million revenue limit


• NAICS 541512 (IT Consulting): $34 million revenue limit


• NAICS 236220 (Commercial Building Construction): $45 million revenue limit

Choose the wrong primary code and you might not qualify for small business set-asides worth billions in reserved contracts.

2. Opportunity Discovery
Government agencies search for contractors by NAICS code. When an agency posts a solicitation for NAICS 541611 (Management Consulting), only businesses registered with that code will receive alerts and appear in contractor searches.

3. Set-Aside Eligibility
Set-aside contracts reserved for small businesses are tied to NAICS codes. You must be small according to the NAICS code specified in the solicitation, not your primary code.

4. Past Performance Evaluation
Agencies evaluate your relevant past performance based on contracts in the same or similar NAICS codes. Having the right codes helps demonstrate relevant experience.

5. Vendor Database Matching
Your NAICS codes in SAM.gov determine:

• Which agency searches include your business


• What contract opportunities you receive alerts for


• How you are categorized in vendor directories


• Which small business liaisons contact you

The NAICS System Basics

NAICS codes are hierarchical with 6 digits:

• First 2 digits: Sector (e.g., 54 = Professional, Scientific, Technical Services)


• First 3 digits: Subsector (e.g., 541 = Professional, Scientific, Technical Services)


• First 4 digits: Industry Group (e.g., 5415 = Computer Systems Design and Related Services)


• First 5 digits: Industry (e.g., 54151 = Computer Systems Design and Related Services)


• All 6 digits: Specific Industry (e.g., 541512 = Computer Systems Design Services)

The more specific the code (more digits), the more precisely it describes your business activity.

NAICS Codes in Practice

When you register in SAM.gov, you'll:

Select your primary NAICS code - determines your size standard

Add additional NAICS codes - up to 1,000 codes for other products/services you offer

Update codes as your business evolves

Understanding NAICS codes is fundamental to government contracting success. Choose well, and you'll qualify for set-asides and be discoverable by agencies. Choose poorly, and you'll miss opportunities or be ineligible for contracts you could have won.

NAICS codes follow a logical hierarchical structure. Understanding this structure helps you find the right codes for your business and navigate the classification system.

The 6-Digit Hierarchy

NAICS uses a 6-digit system where each level adds specificity:

Sector (2 digits)
The broadest category. There are 20 sectors:

• 11: Agriculture, Forestry, Fishing


• 21: Mining, Quarrying, Oil and Gas


• 23: Construction


• 31-33: Manufacturing


• 42: Wholesale Trade


• 44-45: Retail Trade


• 48-49: Transportation and Warehousing


• 51: Information


• 52: Finance and Insurance


• 53: Real Estate and Rental


• 54: Professional, Scientific, Technical Services


• 55: Management of Companies


• 56: Administrative and Support Services


• 61: Educational Services


• 62: Health Care and Social Assistance


• 71: Arts, Entertainment, Recreation


• 72: Accommodation and Food Services


• 81: Other Services (except Public Administration)


• 92: Public Administration

Subsector (3 digits)
Narrows the sector. Example in Sector 54 (Professional Services):

• 541: Professional, Scientific, and Technical Services

Industry Group (4 digits)
Further refinement. Example:

• 5415: Computer Systems Design and Related Services


• 5416: Management, Scientific, Technical Consulting


• 5417: Scientific Research and Development

NAICS Industry (5 digits)
More specific classification. Example under 5415:

• 54151: Computer Systems Design and Related Services

National Industry (6 digits)
Most specific level. Example:

• 541511: Custom Computer Programming Services


• 541512: Computer Systems Design Services


• 541513: Computer Facilities Management Services


• 541519: Other Computer Related Services

Example: IT Consulting Business

Let's trace a computer systems design company through the hierarchy:

• 54: Professional, Scientific, Technical Services (Sector)


• 541: Professional, Scientific, Technical Services (Subsector)


• 5415: Computer Systems Design and Related Services (Industry Group)


• 54151: Computer Systems Design and Related Services (NAICS Industry)


• 541512: Computer Systems Design Services (National Industry)

Each level adds precision about what the business actually does.

Related vs. Different Codes

Related Codes (share first 3-4 digits):

• 541511: Custom Computer Programming


• 541512: Computer Systems Design


• 541519: Other Computer Related Services

These are in the same industry group, so they are considered related. Past performance in 541511 is relevant when bidding on a 541512 contract.

Different Codes (different sectors):

• 541512: Computer Systems Design (Sector 54)


• 236220: Commercial Building Construction (Sector 23)


• 561720: Janitorial Services (Sector 56)

These are unrelated industries. Past performance in one does not help with the others.

Size Standards Tied to NAICS

Every 6-digit NAICS code has a specific small business size standard set by the SBA:

Revenue-Based Standards (Most Service Industries)

• 541330 (Engineering): $25.5 million


• 541512 (IT Consulting): $34 million


• 541611 (Management Consulting): $25.5 million


• 561720 (Janitorial): $25.5 million

Employee-Based Standards (Most Manufacturing)

• 332710 (Machine Shops): 1,000 employees


• 333318 (Other Industrial Machinery): 1,250 employees


• 334111 (Electronic Computers): 1,250 employees

Why This Matters
A company with $30 million in revenue:

• IS small business for NAICS 541512 (Computer Systems Design - $34M limit)


• IS NOT small business for NAICS 541330 (Engineering - $25.5M limit)

Choose your primary NAICS code strategically to maintain small business status.

NAICS Updates Every 5 Years

The NAICS system is reviewed and updated every 5 years to reflect economic changes:

• 2017 NAICS


• 2022 NAICS (current)


• 2027 NAICS (next update)

Updates include:

• New codes for emerging industries (e.g., cannabis, cryptocurrency services)


• Consolidated codes for declining industries


• Modified definitions to reflect technological changes


• Updated size standards

Check your codes after each update to ensure they still accurately reflect your business. Some codes split, merge, or change definitions.

Finding Codes in the Hierarchy

To find your codes:

Start with sector (what broad industry are you in?)

Navigate subsector (more specific category)

Review industry group descriptions

Identify specific 6-digit codes that match your work

Use the official NAICS search tool to browse the hierarchy and read detailed code descriptions.

Pro Tip: Don't just pick codes based on the title. Read the full definition and examples to ensure it accurately describes your business activities. Many code titles are misleading without the full definition.

Finding the right NAICS codes is crucial. Here's how to identify which codes accurately represent your business:

Method 1: Official NAICS Search Tool (Recommended)

Website: census.gov/naics

Go to the official U.S. Census Bureau NAICS site

Click 2022 NAICS Search (or current year)

Search by:

- Keyword: Enter your business activity (e.g., web design, janitorial) - Code: Enter a code if you have a partial number - Hierarchy: Browse the tree structure

Review results carefully:

- Read full code descriptions, not just titles - Check illustrative examples - Verify cross-references to related codes

Method 2: NAICS Association Tool

Website: naics.com

This free resource offers:

• Search by business activity description


• Browse industries alphabetically


• View size standards alongside codes


• More user-friendly than the census site

How to use:

Enter what your business does in plain language

Review suggested codes

Click each code to see full definition and examples

Check if you qualify as small business for each code

Method 3: Ask What Your Customers Buy

Think about how your customers would describe what they are purchasing:

Example 1: IT Consultant
What customers buy: Computer systems design and integration services
Likely codes:

• 541512: Computer Systems Design Services


• 541519: Other Computer Related Services


• 541511: Custom Computer Programming (if you develop software)

Example 2: Janitorial Company
What customers buy: Building cleaning and maintenance
Likely codes:

• 561720: Janitorial Services


• 561790: Other Services to Buildings (if you do maintenance beyond cleaning)

Example 3: Marketing Consultant
What customers buy: Marketing strategy and advertising services
Likely codes:

• 541613: Marketing Consulting Services


• 541810: Advertising Agencies


• 541820: Public Relations Agencies

Method 4: Research Competitors

Find companies similar to yours and check their NAICS codes:

In SAM.gov:

Search Dynamic Small Business Search (DSBS)

Search by keywords related to your industry

View competitor profiles

Note which NAICS codes they have selected

Read the code definitions to see if they fit your business too

On USAspending.gov:

Search for contracts in your industry

View contract details

Note the NAICS codes used in solicitations

See which codes are common for contracts you'd want to bid on

Method 5: Review Past Solicitations

Look at actual government solicitations for work you'd bid on:

Go to sam.gov contract opportunities

Search keywords for your services

Open relevant solicitations

Note the NAICS codes specified

Add those codes to your list

Common Codes by Industry Category

Construction:

• 236220: Commercial and Institutional Building Construction


• 237310: Highway, Street, and Bridge Construction


• 238210: Electrical Contractors


• 238220: Plumbing, Heating, Air-Conditioning Contractors

Information Technology:

• 541511: Custom Computer Programming Services


• 541512: Computer Systems Design Services


• 541513: Computer Facilities Management Services


• 541519: Other Computer Related Services


• 518210: Data Processing, Hosting, and Related Services

Professional Services:

• 541330: Engineering Services


• 541611: Administrative Management and General Management Consulting


• 541612: Human Resources Consulting


• 541613: Marketing Consulting Services


• 541618: Other Management Consulting Services


• 541990: All Other Professional, Scientific, and Technical Services

Facilities Services:

• 561210: Facilities Support Services


• 561720: Janitorial Services


• 561730: Landscaping Services


• 561790: Other Services to Buildings and Dwellings

Security Services:

• 561612: Security Guards and Patrol Services


• 561621: Security Systems Services

Healthcare:

• 621111: Offices of Physicians


• 621399: Offices of All Other Miscellaneous Health Practitioners


• 621910: Ambulance Services

Transportation:

• 484110: General Freight Trucking, Local


• 484121: General Freight Trucking, Long-Distance, Truckload


• 488510: Freight Transportation Arrangement

Manufacturing:

• 332710: Machine Shops


• 333318: Other Commercial and Service Industry Machinery Manufacturing


• 336411: Aircraft Manufacturing

Choosing Between Similar Codes

Sometimes multiple codes seem applicable. Here's how to choose:

Read Full Definitions
Code titles can be misleading. Always read:

• The complete definition


• Illustrative examples


• Cross-references


• Exclusions

Example Dilemma: Marketing Firm

• 541613: Marketing Consulting Services (strategy and planning)


• 541810: Advertising Agencies (creative and media placement)


• 541820: Public Relations Agencies (media relations and reputation)

If you do all three, you might select:

• Primary: 541613 (if marketing strategy is your largest revenue source)


• Additional: 541810, 541820 (to appear in searches for those services)

Consider Size Standards
If two codes both fit your business, choose the primary code with the higher size standard so you maintain small business eligibility longer.

Verify with IRS and State

Your NAICS codes should generally align with:

• How you are classified for tax purposes


• Your business license category


• Your SBA loan documents (if applicable)

Misalignment can cause confusion during audits or certification applications.

Common Mistakes When Selecting Codes

Mistake #1: Choosing Aspirational Codes
Don't select codes for services you want to offer someday. Only choose codes for capabilities you can actually perform now.

Mistake #2: Choosing Too Many Codes
More is not better. Agencies may question if you can really do 50+ different things. Focus on what you actually do.

Mistake #3: Ignoring Size Standards
Your primary code determines eligibility. Don't choose a code where you exceed the size standard.

Mistake #4: Using Outdated Codes
Check you are using the current NAICS year (2022 as of this guide). Some codes change every 5 years.

Mistake #5: Not Reading Full Definitions
Code 541990 sounds like a catch-all, but it excludes many services defined elsewhere. Always read the full definition.

Getting Help

If you are still unsure:

• Contact your local Small Business Development Center (SBDC)


• Call SBA Answer Desk: 1-800-827-5722


• Consult with a government contracting specialist


• Review our Government Contracting 101 guide

Pro Tip: Start with 3-5 codes that precisely match your current capabilities. You can always add more codes later in SAM.gov as your business grows or pivots. It's better to be focused than to claim expertise in dozens of unrelated codes.

Your primary NAICS code is the single most important code you'll select. It determines whether you qualify as a small business, which directly affects your eligibility for billions in set-aside contracts.

What Makes a Code Primary?

Your primary NAICS code should represent:

Your largest revenue source in the past 3 fiscal years

The business activity that generates the most income

What you spend the most time doing

This is not what you want to do or hope to do - it is what you actually do now.

Why Primary Code Matters

1. Small Business Size Standard Determination
Your primary code's size standard determines if you are a small business:

Example: A company with $30M in annual revenue

• Primary code 541512 (IT Consulting - $34M limit): QUALIFIES as small business


• Primary code 541330 (Engineering - $25.5M limit): DOES NOT qualify

This difference determines eligibility for:

• Small business set-asides


• 8(a) program eligibility


• HUBZone contracts


• WOSB/EDWOSB set-asides


• SDVOSB set-asides

2. Representation in SAM.gov
Your primary code appears prominently in SAM.gov and the Dynamic Small Business Search (DSBS), influencing how agencies discover you.

3. SBA Certification Applications
When applying for 8(a), HUBZone, or other SBA certifications, your primary code is verified and must align with your actual business activities and revenue.

4. Size Standard Protests
If a competitor protests your small business status on a contract, the contracting officer will examine your primary NAICS code and whether you meet its size standard.

How to Choose Your Primary Code

Step 1: Calculate Revenue by NAICS Code

Review your revenue for the past 3 fiscal years:

Example: Diversified Tech Company
| NAICS Code | Description | 3-Year Avg Revenue |
|------------|-------------|-------------------|
| 541512 | IT Consulting | $18M (60%) |
| 541511 | Custom Programming | $9M (30%) |
| 541519 | Other Computer Services | $3M (10%) |

Primary code: 541512 (highest revenue)

Step 2: Check Size Standard

Verify you qualify as small business under your primary code:

• Go to sba.gov/size-standards


• Find your primary NAICS code


• Compare your company to the standard

Step 3: Consider Affiliations

SBA size standards include affiliated companies. Your size calculation includes:

• Parent companies


• Subsidiary companies


• Companies with common ownership/control


• Companies with certain business relationships

Example:
Your IT consulting company: $18M revenue
Your spouse's marketing company: $12M revenue
If SBA considers these affiliated: Combined $30M

This might exceed certain size standards. Consult an attorney if you have affiliated entities.

Step 4: Align with Tax Returns

Your primary NAICS code should generally match:

• Box 2 on your business tax return (Form 1120, 1120-S, or 1065)


• Your business classification for state taxes


• What you told the IRS is your principal business activity

Misalignment can trigger questions during audits or protests.

Strategic Considerations

Size Standard Optimization

If you are near the size threshold, strategic primary code selection matters:

Scenario: Company with $32M revenue

Option A: Primary Code 541611 (Management Consulting)

• Size standard: $25.5M


• Result: NOT small business for most contracts


• Impact: Cannot compete for small business set-asides

Option B: Primary Code 541512 (Computer Systems Design)

• Size standard: $34M


• Result: QUALIFIES as small business


• Impact: Can compete for set-asides, access to SBA programs

Legal requirement: Your choice must be defensible based on actual revenue sources. If management consulting is clearly your largest revenue source, you cannot claim IT is primary just for a better size standard.

Growth Trajectory

Consider where your revenue is trending:

Example: Transitioning Business

• Historical (past 3 years): 60% engineering, 40% IT consulting


• Current year: 45% engineering, 55% IT consulting


• Primary code: Still engineering (based on 3-year average)


• Next year: Can switch to IT consulting if trend continues

You can update your primary NAICS code as your business mix changes.

Contract-Specific NAICS Codes

Important: The solicitation's NAICS code determines eligibility for that specific contract, not your primary code.

Example:

• Your primary code: 541512 (IT Consulting, $34M size standard)


• Your revenue: $30M


• Solicitation NAICS: 541330 (Engineering, $25.5M size standard)


• You do NOT qualify as small business for this contract (even though you are small under your primary code)

This is why having revenue under multiple NAICS codes requires careful tracking.

Updating Your Primary Code

You should update your primary NAICS code in SAM.gov when:

• Your revenue mix fundamentally changes


• You pivot to a new line of business


• Your primary code is no longer accurate

How to update:

Log into SAM.gov

Update your entity registration

Change primary NAICS code

Submit updated registration

Wait for validation (5-10 business days)

Certification Impact:
If you have SBA certifications (8(a), HUBZone, WOSB), changing your primary NAICS code may affect your certification. Consult SBA before making changes.

Common Primary Code Mistakes

Mistake #1: Choosing Based on Opportunities, Not Revenue
Don't choose a primary code because you see lots of solicitations in that category. Choose based on your actual revenue.

Mistake #2: Ignoring Affiliation Rules
Thinking you are under the size standard when affiliated entities push you over.

Mistake #3: Not Documenting Revenue Allocation
If questioned, you need to prove your primary code choice with financial records.

Mistake #4: Using Catch-All Codes
Codes like 541990 (All Other Professional Services) are vague and may trigger scrutiny. Use specific codes when possible.

Mistake #5: Forgetting to Update
Your business mix changes, but your primary code stays the same for years, becoming inaccurate.

Size Standard Protests

Competitors can challenge your small business status. If protested:

Contracting officer refers protest to SBA

SBA examines your primary NAICS code

SBA reviews your revenue/employee count

SBA investigates affiliations

SBA issues determination (you are small or you are not)

Defense: Maintain clear records showing:

• Revenue by NAICS code


• How you calculated your primary code


• Why your size calculation is correct


• Documentation of affiliation analysis

Pro Tip: Even if you are well under the size standard now, document your revenue by NAICS code annually. This creates a defensible record if you are ever protested or audited. Use your accounting software to tag revenue by the NAICS code it was earned under.

While you have one primary NAICS code, you can (and should) register additional codes in SAM.gov for all products and services you offer. Here's how to use a multiple codes strategy effectively.

How Many Codes Can You Have?

• SAM.gov limit: Up to 1,000 NAICS codes
• Practical limit: 5-20 codes for most businesses
• Recommended starting point: 3-5 core codes

Why Add Multiple Codes?

1. Opportunity Discovery
Government agencies search for contractors by NAICS code. More relevant codes = more opportunities.

Example: IT Company

• 541512: Computer Systems Design Services (primary)


• 541511: Custom Computer Programming Services


• 541519: Other Computer Related Services


• 518210: Data Processing and Hosting

This company will appear in searches for all four codes, catching more opportunities than if they only listed their primary code.

2. Contract-Specific Size Standards
Each solicitation specifies a NAICS code with its own size standard. Additional codes let you bid on more contracts.

Example: Company with $30M revenue
Registered codes and size standards:

• 541512 (Computer Systems Design): $34M - qualifies as small


• 541330 (Engineering Services): $25.5M - does NOT qualify


• 541690 (Other Scientific/Technical): $25.5M - does NOT qualify

They can bid as small business on 541512 contracts, but not the others.

3. Demonstrate Capabilities
Multiple related codes show breadth of expertise.

Example: Construction Company

• 236220: Commercial Building Construction (primary)


• 238210: Electrical Contractors


• 238220: Plumbing, HVAC Contractors


• 238290: Other Building Equipment Contractors

Shows they can be prime on commercial construction OR subcontract on specialty trades.

4. Past Performance Relevance
Contracts performed under related NAICS codes count as relevant past performance.

Example: Consulting Firm

• 541611: General Management Consulting (primary)


• 541612: Human Resources Consulting


• 541614: Process/Logistics Consulting


• 541618: Other Management Consulting

Past performance under 541612 is considered relevant for 541611 contracts since they are in the same industry group.

Which Additional Codes to Select

Tier 1: Core Capabilities (Must Have)
Services/products you actively market and have delivered in the past year.

Example: Web Development Company

• 541511: Custom Computer Programming (primary)


• 541512: Computer Systems Design


• 541519: Other Computer Related Services

Tier 2: Regular Capabilities (Should Have)
Services you have delivered before and can readily perform, even if not frequently.

Example: Above Company Adds:

• 541430: Graphic Design Services


• 518210: Web Hosting Services

Tier 3: Adjacent Capabilities (Consider)
Related services you are expanding into or have partial capabilities for.

Example: Above Company Adds:

• 541990: All Other Professional, Scientific, Technical Services


• 511210: Software Publishers

Do Not Add:

• Codes for services you cannot actually perform


• Completely unrelated codes just to appear in more searches


• Codes where you have never done the work and have no capability

Strategic Selection by Industry

Construction Companies
Start with primary construction type, add specialty trades:

• 236220: Commercial Building Construction


• 238210: Electrical


• 238220: Plumbing/HVAC


• 238290: Other Building Equipment


• 238910: Site Preparation Contractors

IT Services Companies
Cover the spectrum of IT work:

• 541511: Custom Programming


• 541512: Systems Design


• 541513: Facilities Management


• 541519: Other Computer Services


• 518210: Data Processing/Hosting


• 541990: Other Professional Services

Professional Services Firms
Show depth in consulting areas:

• 541611: Management Consulting (primary)


• 541612: HR Consulting


• 541613: Marketing Consulting


• 541614: Process Consulting


• 541618: Other Management Consulting


• 541990: All Other Professional Services

Janitorial/Facilities Companies
Cover building services:

• 561720: Janitorial Services


• 561730: Landscaping Services


• 561790: Other Services to Buildings


• 562111: Solid Waste Collection

How Multiple Codes Affect Set-Asides

Small Business Set-Asides
You must be small according to the solicitation's NAICS code, regardless of your primary code.

Example: Company with $32M revenue

• Primary code 541512 ($34M size standard) - SMALL


• Bidding on solicitation with NAICS 541611 ($25.5M standard) - NOT SMALL


• Result: Cannot compete for small business set-aside

Certification Set-Asides (8(a), HUBZone, WOSB, SDVOSB)
Same rule - must be small under the solicitation's NAICS code.

Sole Source 8(a) Contracts
8(a) firms can receive sole-source awards up to $4.5M (goods) or $7M (services) in their certified NAICS codes.

Your 8(a) certification lists specific NAICS codes. You can only receive 8(a) sole-source contracts in those codes.

Managing Your NAICS Codes

In SAM.gov:

Primary code appears first, most prominent

Additional codes listed in the order you select them

All codes are searchable by agencies

Update anytime by modifying your registration

Best Practices:

• Review codes annually during SAM renewal


• Add codes as you gain new capabilities


• Remove codes you no longer perform


• Reorder codes to prioritize your focus areas

Codes and Opportunity Alerts

When you set up saved searches on SAM.gov:

• Filter by specific NAICS codes


• Create separate alerts for each core code


• Set filters by code and contract size


• Monitor solicitations in your registered codes

Common Multiple Codes Mistakes

Mistake #1: Too Many Unrelated Codes
Registering 50+ codes across completely different industries looks unfocused and triggers questions about your actual capabilities.

Fix: Stick to 5-15 codes in related areas you actually perform.

Mistake #2: Forgetting Size Standards Vary
Assuming if you are small under your primary code, you are small for all contracts.

Fix: Always check the solicitation's NAICS code and verify you meet that size standard before bidding.

Mistake #3: Not Having Proof
Claiming codes you cannot demonstrate capability in.

Fix: Only select codes where you have:

• Past performance (contracts or commercial work)


• Staff with relevant skills


• Equipment/resources to perform


• References who can verify capability

Mistake #4: Static Code List
Setting codes once and never updating as business evolves.

Fix: Review during annual SAM renewal and adjust as capabilities change.

Documenting Your Multiple Codes

Create an internal NAICS codes document:

For each code, track:

• 6-digit NAICS code


• Description


• Size standard


• Your status (small or other than small)


• Past performance examples in this code


• Key staff qualified for this work


• Revenue generated under this code

This documentation helps:

• Defend size status if protested


• Respond to capability questions in proposals


• Guide business development efforts


• Ensure your team knows which codes to bid under

Updating Codes in SAM.gov

When to add new codes:

• You've completed work in a new category


• You've hired expertise in a new area


• You're launching a new service line (and can actually perform it)

When to remove codes:

• You no longer offer that service


• You've exited that market


• You cannot perform that work anymore

How to update:

Log into SAM.gov

Update entity registration

Modify NAICS codes (add, remove, reorder)

Submit update

Wait for validation (typically immediate for code changes)

Pro Tip: Create a NAICS Codes Matrix spreadsheet listing all your codes, size standards, whether you qualify as small, and 2-3 recent projects under each code. Update this quarterly. It makes proposal writing faster (you can quickly cite relevant past performance by code) and helps defend your qualifications if questioned.

Understanding size standards is critical because small business status unlocks access to billions in set-aside contracts. Here's how NAICS codes determine your small business eligibility.

What Are Size Standards?

Size standards are the maximum size a business can be and still qualify as small for government contracting purposes. The Small Business Administration (SBA) sets size standards for every NAICS code based on either:

1. Annual Receipts (Revenue-Based)
Most service industries use revenue-based standards:

• Average annual receipts over the past 3 completed fiscal years


• Ranges from $1M to $47M depending on NAICS code


• Includes revenue from affiliated companies

2. Number of Employees (Employee-Based)
Most manufacturing and some service industries use employee counts:

• Average number of employees over the past 12 months


• Ranges from 100 to 1,500 employees depending on NAICS code


• Includes employees of affiliated companies

Common Size Standards by Industry

Information Technology:

• 541511 (Custom Computer Programming): $34M


• 541512 (Computer Systems Design): $34M


• 541513 (Computer Facilities Management): $47M


• 541519 (Other Computer Services): $34M


• 518210 (Data Processing/Hosting): $47M

Professional Services:

• 541330 (Engineering): $25.5M


• 541611 (Management Consulting): $25.5M


• 541612 (HR Consulting): $25.5M


• 541613 (Marketing Consulting): $25.5M


• 541618 (Other Management Consulting): $25.5M


• 541990 (All Other Professional Services): $25.5M

Construction:

• 236220 (Commercial Building Construction): $45M


• 237310 (Highway/Street/Bridge Construction): $45M


• 238210 (Electrical Contractors): $19M


• 238220 (Plumbing/HVAC): $19M


• 238910 (Site Preparation): $22.5M

Facilities Services:

• 561210 (Facilities Support Services): $47M


• 561720 (Janitorial Services): $25.5M


• 561730 (Landscaping Services): $12M


• 561790 (Other Building Services): $25.5M

Manufacturing (Employee-Based):

• 332710 (Machine Shops): 1,000 employees


• 333318 (Industrial Machinery): 1,250 employees


• 334111 (Electronic Computers): 1,250 employees


• 336411 (Aircraft Manufacturing): 1,500 employees

How Size Standards Are Calculated

Revenue-Based Calculation:

Step 1: Determine 3-Year Period
Use your 3 most recently completed fiscal years.

Example: Company with December 31 fiscal year, calculating in 2026:

• 2025 (completed)


• 2024 (completed)


• 2023 (completed)

Step 2: Calculate Average Annual Receipts
Add total receipts for all 3 years, divide by 3.

Example:

• 2023: $20M


• 2024: $25M


• 2025: $30M


• Average: $25M

Step 3: Include Affiliates
Add revenue from all affiliated companies (companies under common ownership/control).

Example:

• Your company: $25M


• Sister company (same ownership): $8M


• Total for size calculation: $33M

Step 4: Compare to Size Standard
Check your primary NAICS code's size standard.

Example: Primary code 541512 (Computer Systems Design) = $34M standard

• Your size: $33M


• Result: QUALIFIES as small business

Employee-Based Calculation:

Step 1: Determine 12-Month Period
Use the 12 months prior to self-certification or bid submission.

Step 2: Calculate Average Employees

• Add number of employees for each pay period


• Divide by number of pay periods


• Include full-time, part-time, temporary


• Do NOT include independent contractors

Example (bi-weekly pay):

• 26 pay periods in 12 months


• Total employee count across all pay periods: 13,000


• Average: 500 employees

Step 3: Include Affiliates
Add employees from all affiliated companies.

Step 4: Compare to Size Standard

Example: NAICS 332710 (Machine Shops) = 1,000 employee standard

• Your employees: 500


• Result: QUALIFIES as small business

Affiliation Rules

The SBA affiliation rules can make you large even if your company alone is small.

Types of Affiliation:

1. Ownership Affiliation

• One company owns >50% of another


• Common parent company owns >50% of multiple companies

2. Common Management

• Same CEO, president, or managing member controls multiple companies


• Overlapping boards of directors with control

3. Identity of Interest

• Close relatives (spouses, parents, children) own separate businesses


• Former business partners in same industry

4. Newly Organized Concern

• New company formed by former owners/employees of similar company


• May be affiliated with predecessor

5. Joint Ventures

• Joint venture is affiliated with each member company


• Important for teaming on large contracts

Example Scenario: Affiliation Through Ownership

Your IT consulting firm:

• Revenue: $18M


• Primary NAICS: 541512 (size standard $34M)

Your spouse's marketing firm:

• Revenue: $15M


• Primary NAICS: 541613 (size standard $25.5M)

If SBA determines affiliation (identity of interest):

• Combined revenue: $33M


• For 541512 contracts: $33M < $34M = STILL SMALL


• For 541613 contracts: $33M > $25.5M = NOT SMALL

Rebutting Affiliation:

You can argue companies are not affiliated if:

• Separate management (different CEOs, no overlap)


• Separate finances (different banks, no shared funds)


• Separate operations (different offices, equipment, staff)


• No business dealings between the companies


• Fracture between family members (estrangement, legal separation)

When Size Is Determined

Self-Certification in Proposals:
When you submit a bid, you self-certify small business status based on:

• The solicitation's NAICS code (NOT your primary code)


• Your size at the time of bid submission


• Including all affiliates

SBA Review:
Size can be reviewed if:

• Competitor files size protest


• Contracting officer has concerns


• Random SBA audit


• Certification application (8(a), HUBZone, etc.)

Size Protests:

Competitors can challenge your small business status:

Process:

Competitor files protest with contracting officer

Contracting officer forwards to SBA

SBA Area Office investigates

You submit size determination paperwork

SBA issues formal decision (small or other than small)

If found other than small:

• Disqualified from that contract


• May lose other active set-aside contracts


• Added to SBA's list of ineligible contractors


• Damage to reputation

Defense:

• Maintain clear records of revenue by year


• Document affiliation analysis


• Keep organizational charts showing ownership structure


• Retain tax returns and financial statements

Contract-Specific Size Standards

Critical Rule: The solicitation's NAICS code determines eligibility, not your primary code.

Example: Company with $30M average annual revenue

Scenario 1: Solicitation NAICS 541512 (size standard $34M)

• $30M < $34M


• QUALIFIES as small business - can bid on small business set-aside

Scenario 2: Solicitation NAICS 541330 (size standard $25.5M)

• $30M > $25.5M


• DOES NOT qualify as small business - cannot bid on small business set-aside

Same company, same revenue, different eligibility based on solicitation NAICS.

Size Standard Changes

SBA reviews and adjusts size standards periodically:

• Typically every 5 years aligned with NAICS updates


• Can change more frequently based on economic data


• Usually increase over time (inflation-adjusted)

Recent changes:

• 2019: Many IT codes increased from $27.5M to $30M


• 2022: Several construction codes increased


• 2024: Some professional services codes increased to $25.5M

What to do:

• Check current size standards at sba.gov/size-standards


• Monitor SBA announcements for changes


• Update your tracking spreadsheet when standards change


• May regain small business status if standards increase

Special Size Standard Programs

8(a) Program:
Must be small under your primary NAICS code at time of application and throughout the 9-year program term.

HUBZone:
Must be small under your primary NAICS code at time of application.

WOSB/EDWOSB:
Must be small under the solicitation's NAICS code (same as regular small business).

SDVOSB:
Must be small under the solicitation's NAICS code (same as regular small business).

Size Standard Resources

Official SBA Size Standards Tool:
sba.gov/size-standards

• Search by NAICS code


• Download complete table (Excel)


• View methodology

SBA Table of Size Standards:
Published as a searchable table showing every NAICS code and its size standard.

Pro Tip: Create a simple tracking spreadsheet with these columns: NAICS Code | Description | Size Standard | Your Size | Small? (Y/N) | Notes. Update it annually with your 3-year rolling average. This instant reference tells you which set-asides you can bid on and helps you quickly respond to size protests.

NAICS code mistakes can cost you opportunities, disqualify you from set-asides, or trigger size protests. Here are the most common errors and how to avoid them:

Mistake #1: Choosing Codes Based on Opportunities, Not Actual Work

The Problem:
Contractors see lots of solicitations in a particular NAICS code and add it to their profile, even though they have never done that type of work.

Example:
A janitorial company (NAICS 561720) sees many solicitations for 541512 (Computer Systems Design) and adds it hoping to get alerts, even though they do not do IT work.

Why it is bad:

• Agencies may question your capability


• If awarded, you cannot perform


• Wastes time responding to irrelevant opportunities


• Dilutes your actual expertise

Fix:
Only select codes where you have:

• Actual past performance (contracts or commercial work)


• Qualified staff and resources


• Verifiable capability

Mistake #2: Not Understanding That Solicitation NAICS Determines Size

The Problem:
Contractors assume if they are small under their primary NAICS code, they are small for all contracts.

Example:

• Company revenue: $30M


• Primary NAICS: 541512 (Computer Systems Design, $34M size standard) - SMALL


• Bids on solicitation with NAICS 541330 (Engineering, $25.5M size standard)


• Certifies as small business in proposal


• Result: False certification, can be protested and disqualified

Why it is bad:

• False certification is grounds for disqualification


• Can trigger SBA investigation


• Damages reputation with agencies


• May result in suspension/debarment for willful misrepresentation

Fix:

• Always check the solicitation's NAICS code


• Calculate your size against that specific code's standard


• Only certify as small if you meet that code's standard


• Track your size status for each code you have

Mistake #3: Ignoring Affiliation Rules

The Problem:
Calculating size based only on your company, not including affiliated entities.

Example:

• Your construction company: $18M revenue


• Your spouse's engineering firm: $15M revenue


• Size standard for bid: $25.5M


• You certify as small: $18M < $25.5M, I am small!


• SBA finds affiliation: $33M > $25.5M = NOT SMALL


• Result: Protest, disqualification, possible debarment

Why it is bad:

• Affiliation violations are serious


• SBA presumes affiliation in many scenarios (family, common ownership, etc.)


• Burden is on you to prove no affiliation


• Can lose multiple contracts if found affiliated

Fix:

• Identify all potentially affiliated entities


• Calculate size including ALL affiliates


• Document your affiliation analysis


• Consult attorney if complex ownership structures exist

Mistake #4: Selecting Too Many Unrelated Codes

The Problem:
Registering 50+ NAICS codes across completely different industries to maximize opportunity alerts.

Example:

• 541511: Custom Programming


• 236220: Commercial Construction


• 561720: Janitorial Services


• 621111: Physician Offices


• 484110: Freight Trucking

Why it is bad:

• Agencies question if you can really do all these different things


• Looks unfocused and desperate


• Triggers capability concerns


• Dilutes your actual expertise

Fix:

• Stick to 5-15 codes in related areas you actually perform


• Group codes logically (all IT codes, or all construction codes, not mixed)


• Remove codes you no longer perform

Mistake #5: Using the Wrong Primary Code

The Problem:
Choosing a primary code that is not actually your largest revenue source.

Example:

• Revenue: 70% Engineering (541330, size standard $25.5M), 30% IT (541512, size standard $34M)


• Total revenue: $28M


• Selects 541512 as primary to stay under size standard


• SBA reviews for 8(a) application


• Result: Primary code must be Engineering based on revenue - does not qualify for 8(a)

Why it is bad:

• Primary code must reflect actual business mix


• Misrepresentation can void certifications


• Size protests will examine revenue allocation


• Tax return NAICS should generally match

Fix:

• Calculate revenue by NAICS code for past 3 years


• Primary code = highest revenue NAICS


• Document the calculation


• Update as revenue mix changes

Mistake #6: Not Reading Full Code Definitions

The Problem:
Selecting codes based on titles without reading the complete definition.

Example:

• Code 541990: All Other Professional, Scientific, and Technical Services


• Sounds like catch-all for anything professional


• Actually excludes most specific services already defined elsewhere


• Includes only very narrow activities like appraisers, marine surveyors, etc.

Why it is bad:

• Code may not actually cover what you do


• Agencies may question relevance


• Your capability is misrepresented

Fix:

• Read the complete definition at census.gov/naics


• Review illustrative examples


• Check cross-references and exclusions


• If in doubt, use the more specific code

Mistake #7: Forgetting to Update Codes Over Time

The Problem:
Setting NAICS codes once in SAM.gov and never updating as business evolves.

Example:

• Started as web design firm (541430) in 2018


• Pivoted to cybersecurity consulting (541512) in 2020


• SAM.gov still shows 541430 as primary in 2026


• Missing all cybersecurity opportunities

Why it is bad:

• Agencies will not find you for current services


• Miss relevant opportunity alerts


• Primary code no longer reflects actual revenue


• Past performance in current code not recognized

Fix:

• Review codes annually during SAM.gov renewal


• Add codes as you gain new capabilities


• Remove codes you no longer perform


• Update primary code if revenue mix shifts

Mistake #8: Not Tracking Size Status by Code

The Problem:
Not maintaining a reference of which codes you qualify as small under.

Example:
Company with $32M revenue has codes:

• 541512 ($34M standard) - SMALL


• 541330 ($25.5M standard) - NOT SMALL


• 541611 ($25.5M standard) - NOT SMALL

Bids on 541330 set-aside without checking, gets protested.

Why it is bad:

• Wastes time bidding on ineligible contracts


• False certifications if you claim small business status


• Size protests disrupt operations and damage reputation

Fix:

• Create NAICS tracking spreadsheet


• List: Code | Description | Size Standard | Your Size | Qualifies? Y/N


• Update annually with 3-year rolling average


• Check before bidding on any set-aside

Mistake #9: Claiming Codes Without Past Performance

The Problem:
Adding codes you are capable of but have never actually performed.

Example:

• Custom programming firm (541511) adds NAICS 541330 (Engineering)


• Has engineering degree but no engineering projects


• Bids on engineering contract


• Proposal asks for past performance in 541330 or related codes


• Has none to provide

Why it is bad:

• Cannot demonstrate capability


• Weak proposals with no relevant past performance


• Wastes time on unwinnable bids

Fix:

• Only add codes where you have completed work


• Build past performance through subcontracting first if needed


• Start with commercial projects to demonstrate capability


• Add code only after you have proof of performance

Mistake #10: Not Aligning Codes with Tax Returns

The Problem:
NAICS code in SAM.gov does not match what is reported to IRS.

Example:

• Tax return shows primary business activity: 541611 (Management Consulting)


• SAM.gov primary code: 541512 (Computer Systems Design)


• Significant discrepancy

Why it is bad:

• Triggers questions during audits


• Size protests will examine tax returns


• 8(a) and other certifications verify tax return alignment


• May indicate misrepresentation

Fix:

• Align SAM.gov primary code with tax return principal business activity


• If they differ, be prepared to explain why (e.g., recent business pivot)


• Update tax classification if business has changed

Preventing NAICS Code Mistakes

Create a NAICS Code Playbook:

Document for each code you use:

• 6-digit NAICS code


• Complete definition


• Size standard


• Your size status (small or other than small)


• Past performance examples (3+ projects)


• Key personnel qualified for this work


• When you added this code


• Revenue under this code (if tracked)

Annual Review Process:

During SAM.gov renewal:

Review all registered codes

Remove codes you no longer perform

Add new codes for new capabilities

Update primary code if revenue mix changed

Recalculate size status with current 3-year average

Update tracking spreadsheet

Before Every Bid:

Note solicitation NAICS code

Verify you qualify as small under that code (if set-aside)

Confirm you have relevant past performance

Ensure code is in your SAM.gov profile

Can demonstrate capability if asked

Pro Tip: Set a calendar reminder each year on your company's fiscal year end date to recalculate your 3-year average revenue and update your NAICS size status tracking sheet. This ensures you always know which set-asides you can bid on without having to calculate on the fly when a hot opportunity drops.

Now that you understand NAICS codes, here's how to put that knowledge into action:

Immediate Actions (This Week)

1. Identify Your NAICS Codes

• Use the official NAICS search tool


• Search by what you do, not what you are


• Write down 3-5 codes that match your actual work


• Read the full definition for each code

2. Determine Your Primary Code

• Calculate revenue by NAICS code for past 3 fiscal years


• Primary = highest revenue code


• Verify this aligns with your tax return


• Check the size standard for your primary code

3. Check Your Small Business Status

• Look up size standard for each code at sba.gov/size-standards


• Calculate your size (3-year average revenue or 12-month average employees)


• Include affiliated companies in calculation


• Determine: Small or Other Than Small for each code

4. Update Your SAM.gov Registration
If you already have SAM.gov registration:

• Log in and review your NAICS codes


• Update primary code if needed


• Add missing codes for services you actually perform


• Remove codes you no longer do


• Submit update

If you do not have SAM.gov registration yet:

• Review our SAM.gov registration guide


• Have your NAICS codes ready before starting


• Complete registration with accurate codes

Short-Term Actions (Next 30 Days)

1. Create NAICS Tracking Spreadsheet

Build a reference document with columns:

• NAICS Code (6 digits)


• Description


• Size Standard (revenue or employees)


• Your Size (3-year average)


• Small? (Y/N)


• Past Performance (2-3 examples)


• Date Added

2. Document Past Performance by Code

For each NAICS code you claim:

• List 2-3 relevant projects (contract or commercial)


• Note contract value, customer, completion date


• Identify references who can verify


• This becomes your capability proof

3. Set Up Opportunity Alerts

In SAM.gov contract opportunities:

• Create saved searches for each core NAICS code


• Filter by: NAICS code, contract size, set-aside type, location


• Enable email notifications


• Review opportunities weekly

4. Research Target Agencies

Use USAspending.gov to find agencies that buy your services:

• Search by your NAICS codes


• Identify top spending agencies


• Review contract sizes and award history


• Note which codes are most active

Medium-Term Actions (60-90 Days)

1. Build Past Performance in Weak Codes

If you have NAICS codes with limited past performance:

• Target smaller contracts to build track record


• Consider subcontracting to gain experience


• Accept commercial work to demonstrate capability


• Document everything for future proposals

2. Optimize Code Selection

Review your codes strategically:

• Are you missing codes for services you offer?


• Do you have codes you cannot actually perform?


• Are there better codes with higher size standards?


• Should you add adjacent capabilities?

3. Monitor Size Standard Changes

• Subscribe to SBA announcements
• Check for NAICS updates (every 5 years)
• Recalculate size if standards change
• You may gain small business status if standards increase

4. Consider Certifications

If eligible, apply for small business certifications:

• Review our small business certifications guide


• 8(a), HUBZone, WOSB, SDVOSB programs


• Certifications tied to NAICS codes


• Dramatically improve win rates on set-asides

Annual Maintenance

During SAM.gov Renewal (Every Year):

Recalculate 3-year average revenue

Update size status for each code

Review all NAICS codes for accuracy

Add new codes for new capabilities

Remove codes you no longer perform

Check if primary code should change

Verify alignment with tax return

Update tracking spreadsheet

After Fiscal Year End:

Calculate revenue by NAICS code for completed year

Update 3-year rolling average

Determine if size status changed

Assess if primary code should change

Plan capability development for next year

Advanced Strategies

Size Standard Optimization

As you approach size limits:

• Monitor which codes you'll graduate from


• Plan transition to unrestricted competition


• Build past performance before losing small business status


• Consider business structure changes (spin-offs, separate entities)


• Consult attorney on affiliation implications

Multiple Entity Strategy

Some businesses create separate entities for different NAICS codes to:

• Maintain small business status longer


• Avoid affiliation on certain contracts


• Separate high-risk from stable businesses

Warning: This is complex and has legal implications. Consult an attorney specializing in government contracts before creating affiliated entities.

Helpful Resources

Continue Learning:

• Government Contracting 101 - Overall beginner's guide


• SAM.gov Registration Guide - Register with your codes


• Small Business Certifications - Leverage your codes for set-asides


• Set-Aside Contracts Guide - Understand how size/codes affect eligibility

Browse Opportunities:

• Federal contracting opportunities - Federal agencies


• State portals directory - State and local contracts


• Search by your NAICS codes to find relevant opportunities

NAICS Code Tools:

• Official NAICS Search - Census Bureau


• SBA Size Standards - Look up size limits


• NAICS Association - User-friendly search


• USAspending.gov - Research contracts by NAICS

Automate Opportunity Finding

Manually searching multiple NAICS codes across SAM.gov and state portals is time-consuming. GovContractScout automatically matches opportunities to your NAICS codes and sends daily alerts, so you never miss relevant contracts.

Final Tips

Start Simple
Don't overcomplicate it. Start with 3-5 NAICS codes you know you can perform, register in SAM.gov, and start bidding. You can always add more codes later.

Accuracy Over Quantity
Better to have 5 accurate codes with strong past performance than 50 codes you cannot defend.

Document Everything
Maintain records showing:

• Revenue by NAICS code


• Size calculations including affiliates


• Past performance by code


• When/why you added each code

Stay Compliant

• Never falsely certify small business status


• Update codes as your business evolves


• Include affiliates in size calculations


• Be honest about your capabilities

Get Help If Needed

• Local Small Business Development Center (SBDC)


• PTAC (Procurement Technical Assistance Center)


• SBA Answer Desk: 1-800-827-5722


• Government contracting attorney for complex situations

You now have the knowledge to select, manage, and leverage NAICS codes for government contracting success. Your codes are the bridge between your capabilities and the billions in opportunities agencies post every year. Choose wisely, maintain them diligently, and use them strategically.

Find opportunities matched to your NAICS codes with GovContractScout →