621999 — All Other Miscellaneous Ambulatory Health Care Services
Description
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) (as defined in the official U.S. Census Bureau 2022 NAICS Manual).
Illustrative Examples
- Health screening services (except by offices of health practitioners)
- Physical fitness evaluation services (except by offices of health practitioners)
- Hearing testing services (except by offices of audiologists)
- Smoking cessation programs
- Pacemaker monitoring services
Exclusions & Cross-References
- Establishments primarily engaged in the independent practice of medicine are classified in Industry 62111,
- Offices of Physicians;
- Establishments primarily engaged in the independent practice of dentistry are classified in Industry 621210,
- Offices of Dentists;
- Establishments primarily engaged in the independent practice of health care (except offices of physicians
- and dentists) are classified in Industry Group 6213, Offices of Other Health Practitioners;
- Establishments primarily engaged in providing general or specialized outpatient care services are classified
- in Industry Group 6214, Outpatient Care Centers;
- Establishments primarily engaged in providing home health care services are classified in Industry 621610,
- Home Health Care Services;
- Establishments primarily engaged in the transportation of patients by ground or air, along with medical
- care, are classified in Industry 621910, Ambulance Services;
Overview Facts
Legacy SIC Concordance
Trace the historical mapping chain from the 1987 Standard Industrial Classification (SIC) to the modern 2022 NAICS code format.
- SIC 8099 - Health and Allied Services, NEC (via SIC1987:8099→NAICS1997:621999→2002:621999→2007:621999→2012:621999→2017:621999→2022:621999)
Suggested Product Service Codes (Advisory)
The following Product Service Codes (PSCs) are advisory suggestions aligned with this NAICS code. Note: NAICS and PSC codes map to different dimensions of procurement (industry vs. product/service). There is no official binding 1:1 crosswalk.
- PSC Q999 — Other Medical Services
Source: DoD DPCAP PSC Selection Tool (Ingested: 2026-06-29)
Frequently Asked Questions (FAQ)
Is NAICS code 621999 valid in 2022? ▾
Yes, 621999 is a valid 6-digit 2022 NAICS national industry code representing 'All Other Miscellaneous Ambulatory Health Care Services' under Sector 62 in the official classification index.
What is the SBA size standard for NAICS code 621999? ▾
The Small Business Administration (SBA) has established a small business size standard of $20,500,000 for NAICS code 621999 (All Other Miscellaneous Ambulatory Health Care Services), calculated based on receipts.
What is the legacy SIC equivalent for NAICS 621999? ▾
According to official Census Bureau concordance tables, NAICS code 621999 (All Other Miscellaneous Ambulatory Health Care Services) maps to legacy 1987 Standard Industrial Classification (SIC) codes: 8099 - Health and Allied Services, NEC.
Related Pages & Tools
Further regulatory reference links for NAICS code 621999:
- Sector 62 Directory Hub — List of related industries in the Health Care and Social Assistance sector.
- SIC ↔ NAICS Crosswalk Tool — Look up mappings between legacy SIC codes and modern classifications.
- NAICS 621999 to SIC Crosswalk — Bidirectional mapping to legacy SIC codes (All Other Miscellaneous Ambulatory Health Care Services).
- SBA Size Standards Guide — Complete rules and averaging periods for small business classifications.
- Calculating Annual Receipts Guide — Detailed worked example of revenue calculation rules.
- IRS Principal Business Activity Guide — How NAICS codes map to corporate and entity tax filings.