Installation, repair, and monitoring of electronic security alarm systems — including access control, intrusion detection, and CCTV. Used for federal facility security technology contracts and integrated electronic security work.
What this NAICS code covers
NAICS 561621 is the North American Industry Classification System code that federal contracting officers assign to security systems services (except locksmiths) 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 561621
The most active federal buyers in this NAICS:
- Department of Homeland Security
- GSA
- Department of Defense
- Department of Veterans Affairs
- Department of State (OBO)
Typical contract value
Awards under NAICS 561621 commonly fall in the range $250K – $25M 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 561621 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 561621 opportunities
SAM.gov publishes every federal solicitation with one or more NAICS codes assigned. Filter by 561621 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.