By Outrider Editorial Team · Updated August 20, 2026
Official definition
This industry comprises establishments primarily engaged in providing day-to-day business and other organizational support services (except office administrative services, facilities support services, employment services, business support services, travel arrangement and reservation services, security and investigation services, services to buildings and other structures, packaging and labeling services, and convention and trade show organizing services).
FY2025 obligations
$1.8B
Contract actions
3,211
IDVs
256
Top buying agencies
- Department of Defense$1.5B
- Department of Homeland Security$57.8M
- Department of Energy$54.8M
- Department of State$52.0M
- National Aeronautics and Space Administration$40.0M
FY2025 federal contract obligations, USAspending.gov
NAICS 561990 obligated $1.8 billion in FY2025 across 3,211 contract actions. DoD is $1.5 billion, or 84 percent, with DHS at $58 million, DOE at $55 million, State at $52 million, and NASA at $40 million. The average action is around $570,000, and the dominant crosswalk PSCs are logistics support and aircraft components, which is a strong hint about what actually gets coded here: mission support scopes wrapped around operations that do not fit a named services category.
What belongs here
Day-to-day business and organizational support services that are not office administrative services, facilities support, employment services, business support, travel arrangement, security and investigation, services to buildings, or packaging and labeling.
- Base and installation operations support is 561210.
- Office-level administrative support without operating staff is 561110.
- Professional and technical support that is not clerical is 561499.
Competing in this code
256 IDVs against 3,211 actions is thin coverage, so much of this competes directly. The strategic caution is the same one that applies to every residual code, and it is sharper here because the named alternatives are numerous. A contracting officer arrives at 561990 only after ruling out eight other categories, so buyers do not search it. Hold it as a secondary registration behind whichever named support code describes your delivered service. The exception worth noting: the $16.5 million size standard is low, so when a set-aside does run in this code the small business pool is genuinely small.
Frequently Asked
NAICS 561990 questions, answered.
What is the SBA size standard for NAICS 561990?
SBA sets it at $16.5 million in average annual receipts, averaged over your last five completed fiscal years. Come in at or under that and you are small on every NAICS 561990 solicitation, including the set-asides.
Which agencies buy support services under NAICS 561990?
FY2025 obligations: DoD ($1.5 billion), DHS ($58 million), DOE ($55 million), State ($52 million), NASA ($40 million). DoD at 84 percent, with logistics support as the leading crosswalk PSC, indicates mission support scopes that no named services category cleanly describes.
When is NAICS 561990 the correct code?
Only when eight named support categories all fail to describe the work: office administrative, facilities support, employment, business support, travel arrangement, security and investigation, services to buildings, and packaging and labeling. Contracting officers reach it by elimination, which means buyers rarely search it directly.
Does the low size standard help small businesses in NAICS 561990?
It does when set-asides run. At $16.5 million in average annual receipts, the qualifying pool is genuinely small compared with support codes at $30 million or more. The catch is that DoD holds 84 percent of the $1.8 billion, and much of that sits in large mission support scopes that are not set aside.
Register Under NAICS 561990
Classify your business correctly to maximize visibility to federal buyers and access small business set-asides.
Start Your SAM.gov Registration →