NAICS 2022 subsector USA Verified: Census NAICS 2022 · 2023-03-17
621
NAICS 621 — Ambulatory Health Care Services
Ambulatory Health Care Services
NAICS 621 is the subsector code for ambulatory health care services establishments in the United States. It forms part of the hierarchical North American Industry Classification System maintained by the Census Bureau.
Official data
| Feature | Description |
|---|---|
| Official name | North American Industry Classification System (NAICS) 2022 |
| Issuing authority | U.S. Census Bureau with OMB, Statistics Canada, and INEGI |
| Tax authority | Internal Revenue Service (IRS) |
| Purpose | Statistical business classification and federal contracting (SAM.gov, SBA standards) |
| Used in | SAM.gov registration, SBA size determinations, IRS tax classification, SEC EDGAR (via SIC crosswalk) |
| Active since | 2022 (current edition) |
| Hierarchy level | Sector (2-digit) |
| Source | https://www.census.gov/naics/ |
When do you need NAICS 621?
1 Registering on SAM.gov for federal contracting — enter NAICS 621 as your primary industry code.
2 Checking whether the SBA size standard for ambulatory health care services applies to your business for set-aside contracts or loans.
3 Classifying your main line of business when applying for grants, contracts, loans, or market research surveys.
4 Comparing this code against legacy NAICS 2017 records or related SIC codes for historical data alignment.
NAICS hierarchy path
Trace the classification from the broadest sector down to this national industry code.
Cross-references & crosswalks
How to register a ambulatory health care services business in the US
1
Verify NAICS classification
Confirm that Ambulatory Health Care Services accurately describes your healthcare activity.
2
Obtain state medical board / professional license
Healthcare providers must hold active state professional licenses for their specific discipline.
3
Implement HIPAA compliance program
Covered entities and business associates must maintain HIPAA privacy and security policies, train staff, and conduct risk assessments.
4
Register for NPI number
National Provider Identifier through HHS/CMS — required for billing and electronic healthcare transactions.
5
Apply for Medicare/Medicaid enrollment
If accepting federal healthcare programs, enroll via CMS PECOS or state Medicaid agency.
US Tax Forms & Registration
| Form Name | Who Files It | Frequency |
|---|---|---|
| Profit or Loss from Business | ||
| U.S. Return of Partnership Income | ||
| U.S. Corporation Income Tax Return | ||
| U.S. Income Tax Return for an S Corporation | ||
| Self-Employment Tax | ||
| Estimated Tax for Individuals | ||
| Application for Employer Identification Number (EIN) | ||
| Entity Classification Election | ||
| Nonemployee Compensation | ||
| Employer's Annual Federal Unemployment (FUTA) Tax Return | ||
| Employer's Quarterly Federal Tax Return | ||
| Request for Taxpayer Identification Number and Certification |
Entity Comparison
$
No federal sales tax in the United States. Sales tax is imposed at state and local levels, ranging from 0% to 10.25%. Economic nexus thresholds (following South Dakota v. Wayfair) require out-of-state sellers to collect sales tax once they exceed a state's revenue or transaction threshold, typically $100,000 in sales or 200 transactions per year.
No state income tax: Alaska (AK), Florida (FL), Nevada (NV), New Hampshire (NH), South Dakota (SD), Tennessee (TN), Texas (TX), Washington (WA), Wyoming (WY)
Who uses this code?
Dental Practice Owner
Runs a general or specialty dental office with hygienists, assistants, and front-office staff.
Licenses
- ●State dental license
- ●DEA registration
- ●NPI number
- ●Dental board registration
Tax Forms
- ●Form 1065 or 1120-S
- ●Form 940 (FUTA)
- ●Form 941
Chiropractor
Provides spinal adjustment, wellness care, and rehabilitative therapy in an independent clinic.
Licenses
- ●State chiropractic license
- ●NPI number
- ●Board certification
- ●Malpractice insurance
Tax Forms
- ●Schedule C or 1120-S
- ●Schedule SE
- ●Form 1040-ES
Physical Therapist (Private Practice)
Offers outpatient physical therapy, sports rehab, and post-surgical recovery services.
Licenses
- ●State PT license
- ●NPI number
- ●Medicare enrollment (opt-out or enrolled)
- ●Malpractice insurance
Tax Forms
- ●Schedule C or 1120-S (PLLC)
- ●Schedule SE
- ●Form 1040-ES
Licensed Mental Health Counselor
Provides individual, couples, or family therapy sessions in private practice, in-person and via telehealth.
Licenses
- ●State LPC/LMHC/LCSW license
- ●NPI number
- ●Malpractice insurance
- ●HIPAA compliance
Tax Forms
- ●Schedule C (Form 1040)
- ●Schedule SE (Form 1040)
Who is this code for
Occupations and roles commonly associated with this classification
Also relevant for
Source: O*NET / BLS occupation data · O*NET 30.2 / BLS SOC
Child codes (7)
Frequently asked questions
- What is NAICS 621?
- NAICS 621 is the North American Industry Classification System code for Ambulatory Health Care Services. It classifies this business activity for statistical, regulatory, and government procurement purposes. Federal agencies use NAICS codes to collect and publish data about the US economy, determine SBA size standards, and set aside contracts for small businesses.
- What licenses and permits does a Ambulatory Health Care Services need?
- A Ambulatory Health Care Services typically needs a local business license, a federal EIN from the IRS, and industry-specific permits depending on the sector. Check with your city or county clerk for a general business license, your state's professional or industry licensing board for any required occupational licenses, and your state's tax authority for a sales tax permit if you sell taxable goods or services.
- How do I register a Ambulatory Health Care Services business in the United States?
- To register a Ambulatory Health Care Services business, first choose your legal structure: sole proprietorship (simplest, uses SSN), LLC (personal liability protection, files with your Secretary of State), or corporation (Form 1120 or 1120-S). Register your business name (DBA) with your county if operating under a trade name. Obtain an EIN from the IRS at irs.gov/ein. Register with your state revenue department for any applicable taxes.
- What tax forms does a Ambulatory Health Care Services file with the IRS?
- Tax forms depend on your entity type. A sole proprietor files Schedule C with Form 1040 and Schedule SE for self-employment tax (15.3%). An LLC taxed as a partnership files Form 1065 with Schedule K-1s. A C-Corporation files Form 1120 (21% flat rate). An S-Corporation files Form 1120-S. All businesses paying employees file Form 940 (FUTA) annually and Form 941 quarterly. Estimated tax payments are made via Form 1040-ES four times per year.
- Is Ambulatory Health Care Services the right NAICS code for my business?
- Your NAICS code should reflect your primary business activity — the one generating the most revenue or value. If Ambulatory Health Care Services describes your main line of business, NAICS 621 is likely correct. If you have multiple distinct activities, you may need separate codes for statistical reporting. For federal contracting, your SAM.gov registration should use the code that best matches the work you perform. Review the official NAICS 621 description and exclusions to confirm it fits your operations.
- Does a Ambulatory Health Care Services need an NPI number?
- Yes. Any healthcare provider who transmits health information electronically and is a covered entity under HIPAA must obtain a National Provider Identifier (NPI), a unique 10-digit number issued by CMS. The NPI is used on all standard HIPAA transactions (claims, referrals, prescriptions). Apply at nppes.cms.hhs.gov. There is no fee. Type 1 NPIs are for individual providers; Type 2 NPIs are for organizational providers. You must update your NPI record within 30 days of changes.
- How does a Ambulatory Health Care Services enroll with Medicare and Medicaid?
- Enroll through CMS PECOS (Provider Enrollment, Chain, and Ownership System) online or via paper Form CMS-855. You'll need your NPI, state license, DEA certificate (if prescribing), malpractice insurance, and bank account for EFT payments. Medicare enrollment processes as a Group Practice (CMS-855B) or Individual Practitioner (CMS-855I). Medicaid enrollment is state-specific but uses a common data set. Revalidation is required every 3-5 years. Enrollment can take 60-90 days.
- What is a Business Associate Agreement (BAA) and does a Ambulatory Health Care Services need one?
- A Business Associate Agreement (BAA) is a HIPAA-required contract between a covered entity and any vendor that creates, receives, maintains, or transmits protected health information (PHI) on their behalf. Common BAs include EHR vendors, billing services, cloud hosting, IT support, shredding services, and answering services. The BAA must specify permitted PHI uses, require BA to implement safeguards, report breaches, and ensure subcontractors also comply. BAAs are legally mandatory — working without one is a HIPAA violation.
- What malpractice insurance does a Ambulatory Health Care Services need?
- Medical malpractice (professional liability) insurance is not federally required but is mandatory for hospital privileges, many insurer credentialing panels, and in some states (e.g., Colorado, Connecticut, Kansas, Wisconsin) for specific professions. Policy types: claims-made (covers incidents reported while policy is active) vs. occurrence (covers incidents that happened during the policy period regardless of when claimed). Tail coverage is needed when canceling a claims-made policy. Limits typically range from $1M/$3M (per claim/aggregate) upward.