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

Professional, scientific, or technical services not classified elsewhere — including translation, weather forecasting, and specialised consulting. A frequently-used residual code.

What this NAICS code covers

NAICS 541990 is the North American Industry Classification System code that federal contracting officers assign to all other professional, scientific, and technical services work. The code determines your small-business size standard for any solicitation issued under it, which in turn determines whether you can compete as a small business or pursue any of the socioeconomic set-aside programs.

Federal agencies that buy under NAICS 541990

The most active federal buyers in this NAICS:

• Department of State
• Department of Defense
• USAID
• Department of Justice
• Department of Commerce

Typical contract value

Awards under NAICS 541990 commonly fall in the range $50K – $5M per award, though the distribution is wide — micro-purchases at one end, multi-year IDIQs with $100M+ ceilings at the other. The bulk of activity for small businesses sits in the $250K to $5M range.

Set-aside eligibility

Solicitations under NAICS 541990 are commonly set aside under these programs:

• Small Business
• 8(a)
• HUBZone
• SDVOSB
• WOSB

Eligibility for the program is separate from eligibility for any specific award — you still need to be small under this NAICS’s size standard and meet the program-specific certification (8(a), HUBZone, etc.). The SBA publishes current size standards by NAICS at sba.gov.

Related NAICS codes

How to find NAICS 541990 opportunities

SAM.gov publishes every federal solicitation with one or more NAICS codes assigned. Filter by 541990 for an exact match, or use a search tool with NAICS-aware filtering. WinAContract’s search lets you save NAICS-filtered queries and get email alerts for new postings. State portals use NAICS less consistently — most accept it as a search filter but coverage varies by state. See federal contract search and SAM.gov alternative.