NAICS 541330 vs 541490
This page compares NAICS 541330 (Engineering Services) vs NAICS 541490 (Other Specialized Design Services) to help you determine the correct industry classification code.
Side-by-Side Comparison Asset
| Dimension | NAICS 541330 — Engineering Services | NAICS 541490 — Other Specialized Design Services |
|---|---|---|
| Definition | This industry comprises establishments primarily engaged in applying physical laws and principles of engineering in the design, development, and utilization of machines, materials, instruments, structures, processes, and systems. The assignments undertaken by these establishments may involve any of the following activities: provision of advice, preparation of feasibility studies, preparation of preliminary and final plans and designs, provision of technical services during the construction or installation phase, inspection and evaluation of engineering projects, and related services. | This industry comprises establishments primarily engaged in providing professional design services (except architectural, landscape architecture, engineering, interior, industrial, graphic, and computer systems design). |
| SBA Size Standard | $25,500,000 | $13,500,000 |
| US Establishments (CBP) | 63,233 | 3,469 |
Decision Rule Guidelines
Select 541330 if your primary business focus aligns with Engineering Services. Select 541490 if the establishment's core activities match the definition of Other Specialized Design Services. Verify the revenue share of each activity if both apply.
Frequently Asked Questions (FAQ)
Can I report both NAICS 541330 and 541490 on a business tax return? ▾
No, the IRS requires declaring a single primary activity code (either 541330 or 541490) on Schedule C or Form 1120. You must audit your revenue share between these two classifications and select the code that represents the highest percentage of your receipts.
How do the SBA size standards differ between NAICS 541330 and 541490? ▾
NAICS 541330 has a standard of $25,500,000 while NAICS 541490 has a standard of $13,500,000. Ensure your rolling averages of annual receipts or employees do not exceed the specific code limit for your chosen classification.
Related Pages & Tools
- NAICS Code 541330 Directory — Official definition, SBA thresholds, and details.
- NAICS Code 541490 Directory — Official definition, SBA thresholds, and details.
- Find NAICS by Industry — Search classification directory.
Primary Ingestion Source
Data sourced from the U.S. Census Bureau NAICS 2022 Manual and SBA Small Business Size Regulations (13 CFR Part 121). Last verified on 2026-06-30.