By Outrider Editorial Team · Updated August 20, 2026
Official definition
This U.S. industry comprises establishments primarily engaged in providing ambulatory health care services (except offices of physicians, dentists, and other health practitioners; outpatient care centers; medical and diagnostic laboratories; home health care providers; ambulances; and blood and organ banks).
FY2025 obligations
$337.9M
Contract actions
815
IDVs
108
Top buying agencies
- Department of Defense$152.1M
- Department of Homeland Security$146.9M
- General Services Administration$12.4M
- Department of Agriculture$11.7M
- Department of Transportation$8.0M
FY2025 federal contract obligations, USAspending.gov
NAICS 621999 obligated $338 million in FY2025 across 815 contract actions. DoD is $152 million and DHS is $147 million, which is close to a tie and unusual in any code. GSA and USDA follow at about $12 million each and DOT at $8 million. The DHS share reflects health services delivered in detention and border settings, a requirement with staffing, credentialing, and continuity demands that most clinical staffing firms have never encountered.
What belongs here
Ambulatory health care services that are not offices of physicians, dentists, or other practitioners, not outpatient care centers, not medical and diagnostic laboratories, not home health, not ambulances, and not blood and organ banks. In federal practice it captures on-site clinical services, occupational health programs, and health screening delivered at an agency's own facilities.
- Patient transport with medical care is 621910.
- Diagnostic laboratory work is 621511.
- Clinical services bundled into a facility operations scope may fall under 561210.
Competing in this code
108 IDVs against 815 actions at an average near $415,000 describes substantial multi-year service agreements. The evaluated capability is staffing continuity: agencies are buying reliable clinician coverage at a specific site, and past performance turns on fill rate and credentialing throughput rather than on clinical reputation. The residual nature of the code also means it is easy to miss. Firms delivering on-site occupational health or screening programs frequently register only under physician office or outpatient codes and never see these solicitations.
Frequently Asked
NAICS 621999 questions, answered.
What is the SBA size standard for NAICS 621999?
SBA sets it at $20.5 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 621999 solicitation, including the set-asides.
Which agencies buy other ambulatory health services under NAICS 621999?
FY2025 obligations: DoD ($152 million), DHS ($147 million), GSA ($12 million), USDA ($12 million), DOT ($8 million). DHS nearly matching DoD is the distinctive feature, and that spend covers health services delivered in detention and border settings.
What kind of health services get coded to NAICS 621999?
On-site clinical services, occupational health programs, and health screening delivered at an agency facility, once physician offices, outpatient centers, laboratories, home health, ambulances, and blood and organ banks are all excluded. DHS detention and border health services are the largest civilian example, at $147 million in FY2025.
What do evaluators weight most in this code?
Staffing continuity. Agencies are buying reliable clinician coverage at a named site, so past performance evaluation focuses on fill rate, credentialing throughput, and turnover, well ahead of clinical reputation. The average FY2025 action was near $415,000 across 815 awards, which are multi-year coverage commitments.
Register Under NAICS 621999
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