What is a NAICS code for DBE certification?

NAICS (North American Industry Classification System) codes classify your business by the type of work it performs. The SBA assigns a size standard to each code — your firm must be under that standard to qualify for DBE certification.

Can I have multiple NAICS codes on my DBE certification?

Yes. You can be certified under multiple NAICS codes that reflect the types of work your firm actually performs. However, you must demonstrate competence and track record in each code you request.

Does my NAICS code affect my DBE eligibility?

Yes. Each NAICS code has its own SBA size standard (revenue or employee count). A firm may qualify under one code but not another. Additionally, your firm must meet the USDOT overall gross receipts cap of $30.72 million regardless of your NAICS code.

NAICS Codes for DBE Certification: How to Choose the Right One

Your NAICS code is more than a classification — it determines the SBA size standard that applies to your firm, which directly affects your DBE eligibility. Choosing the wrong code can mean an unnecessary denial. This guide explains what NAICS codes are, how they affect your DBE application, and which codes are most common in California transportation contracting.

Updated April 2026. Verify size standards at sba.gov.

1. What Is a NAICS Code?

NAICS (North American Industry Classification System) is a standardized six-digit numbering system used by the U.S. Census Bureau and federal agencies to classify businesses by their primary type of economic activity. Every business in the country has at least one NAICS code.

For DBE certification, your NAICS code serves two purposes:

It determines the SBA size standard that applies to your firm (13 CFR Part 121). This is the revenue or employee threshold below which your firm qualifies as a "small business."
It defines the types of work your certified DBE firm is listed for in the CUCP statewide directory. Prime contractors search the directory by NAICS code to find subcontractors.

2. Why Your NAICS Code Matters for DBE

DBE eligibility requires meeting two size tests:

Test 1: USDOT Overall Cap

Your firm's average annual gross receipts over the previous five fiscal years cannot exceed $30.72 million. This cap applies to all DBE applicants regardless of industry.

Test 2: SBA Size Standard for Your NAICS Code

Even if you are under $30.72M, you must also meet the SBA size standard for your specific NAICS code. For some industries, this standard is much lower than the overall cap. For example, a marketing firm (NAICS 541613) has a size standard of $19.5M — well below the $30.72M cap.

You must pass both tests. A firm with $25M in annual receipts would pass the USDOT cap but fail the SBA size standard for many service-based NAICS codes.

3. How to Find Your NAICS Code

Check your tax return. Your NAICS code may be listed on Schedule C (sole proprietorship) or your corporate tax return (Form 1120/1120-S). The IRS calls it a "Business Activity Code" or "Principal Business Code."
Search the Census Bureau site. Visit census.gov/naics and search by keyword for your type of work.
Check SBA size standards. Visit the SBA Size Standards Table to find the revenue or employee threshold for your code.
Match your primary revenue source. If your firm performs multiple types of work, your primary NAICS code should reflect the activity that generates the most revenue.

4. Common NAICS Codes for California DBEs

These are among the most frequently used NAICS codes by DBE-certified firms working on Caltrans and transit agency contracts:

NAICS	Description	Size Standard
237310	Highway, Street, and Bridge Construction	$45.0M
238910	Site Preparation Contractors	$22.0M
484220	Specialized Freight Trucking, Local	$34.0M
541330	Engineering Services	$25.5M
541620	Environmental Consulting Services	$19.5M
541370	Surveying and Mapping Services	$19.5M
238210	Electrical Contractors	$22.0M
238120	Structural Steel and Precast Concrete	$22.0M
561730	Landscaping Services	$9.5M
541512	Computer Systems Design Services	$34.0M

Size standards are updated periodically by the SBA. Verify at sba.gov.

5. Understanding Size Standards

SBA size standards are measured in one of two ways depending on the industry:

Revenue-Based (Most Common)

Average annual gross receipts over the previous five fiscal years must be under the threshold for your code. This applies to construction, professional services, trucking, and most other industries.

Employee-Based

Average number of employees over the previous 24 months must be under the threshold. This applies to some manufacturing, mining, and utility codes. Less common in transportation contracting.

Remember: even if your firm is under the SBA size standard for your NAICS code, you must also be under the USDOT overall cap of $30.72M to qualify for DBE certification. Both tests must be met.

6. Requesting Multiple NAICS Codes

You can be certified under multiple NAICS codes if your firm performs different types of work. For example, a construction firm that also provides environmental consulting could be certified under both 237310 and 541620.

To add a NAICS code to your certification, you must demonstrate:

Competence — relevant experience, licenses, equipment, or education for that type of work
Track record — previous contracts or projects in that work category (not always required for new businesses)
Size eligibility — your firm must meet the SBA size standard for each requested code

More NAICS codes = more visibility in the statewide DBE directory. Prime contractors search by code, so being listed under multiple relevant codes increases your chances of being contacted.

7. Common NAICS Code Mistakes

Choosing an overly broad code. Selecting a general code (like 236220 — Commercial Building Construction) when your firm specializes in a narrower area (like 238910 — Site Preparation). The broader code may have a higher size standard, but the agency may challenge your ability to perform that scope of work.

Using the wrong code from your tax return. The IRS code on your tax return may not match the NAICS code that best describes your work for transportation contracts. Review and update if necessary.

Not requesting all relevant codes. If you perform multiple types of work, apply for each applicable code. You can always add codes later, but having them from the start means immediate visibility to more prime contractors.

Ignoring code-specific size standards. A firm with $12M in revenue would qualify under NAICS 237310 ($45M standard) but not under 561730 ($9.5M standard for landscaping). Know the standard for each code you request.

8. Frequently Asked Questions

Q:Can I change my NAICS codes after certification?

Yes. Contact your certifying agency to request adding or removing NAICS codes. You will need to demonstrate competence in any new code you add.

Q:What if my firm does work that spans multiple codes?

Apply for all codes that reflect your actual work. Your primary code should be the one generating the most revenue. Additional codes can be secondary specialties.

Q:Do ACDBE firms use NAICS codes?

The ACDBE program uses different size standards defined in 49 CFR Part 23 ($56.42M for most concessions). However, NAICS codes are still used to classify the type of concession activity for directory purposes.

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