Heavy and civil engineering construction not classified elsewhere — including dams, dredging, marine construction, and other heavy-civil works. Used for federal Corps of Engineers civil-works projects, port construction, and similar specialised infrastructure.
What this NAICS code covers
NAICS 237990 is the North American Industry Classification System code that federal contracting officers assign to other heavy and civil engineering construction 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 237990
The most active federal buyers in this NAICS:
- US Army Corps of Engineers
- Bureau of Reclamation
- US Coast Guard
- Department of Energy
- Department of the Interior
Typical contract value
Awards under NAICS 237990 commonly fall in the range $2M – $250M+ 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 237990 are commonly set aside under these programs:
- Small Business
- 8(a)
- HUBZone
- SDVOSB
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 237990 opportunities
SAM.gov publishes every federal solicitation with one or more NAICS codes assigned. Filter by 237990 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.