NAICS 561990: All Other Support Services — Federal Contracts

What NAICS 561990 covers

The North American Industry Classification System (NAICS) is the standard the federal government uses to classify the industry of every contractor and every procurement. NAICS 561990 identifies businesses primarily engaged in all other support services. When a contracting officer publishes a solicitation on SAM.gov, they tag it with the NAICS code that best matches the work — which is why getting your NAICS portfolio right inside SAM is the single most important step for showing up in agency searches.

Who buys NAICS 561990?

The federal agencies awarding the most contract value to vendors in this NAICS, based on 8 contractors tracked in the Mindy contractor database:

1. 1Dept Of The Navy
2. 2Dept Of The Army
3. 3Dept Of The Air Force
4. 4Federal Acquisition Service
5. 5U.s. Customs And Border Protection

Source: aggregated from the Mindy contractor database (prime contractor disclosures via SBA + agency directories).

Top contractors in NAICS 561990

The largest prime contractors associated with NAICS 561990, ranked by total reported federal contract value. These are your most likely incumbents — and your most likely teaming partners on recompetes:

1. 1
   Sierra Nevada Company LLC

   $12.9B total reported value
2. 2
   General Atomic Technologies Corporation

   $5.6B total reported value
3. 3
   CGI INC

   $983.7M total reported value
4. 4
   Sierra Nevada Corporation

   $311.6M total reported value
5. 5
   Booz Allen Hamilton Holding Corporation

   $237.9M total reported value
6. 6
   Vertex Modernization And Sustainment LLC

   $71.2M total reported value
7. 7
   Nish

   $28.8M total reported value
8. 8
   Didlake INC

   $1.6M total reported value

Values reflect each contractor's aggregate reported federal contract value (across all of their NAICS codes, not just 561990). Use as a ranking signal, not as a per-NAICS award total.