NAICS code for medical billing: 541219, and when coding, practice management or collections change it

This page is for owners of medical billing, coding and revenue cycle companies who need a code for SAM.gov, a bank, an insurer, a payer enrollment or a tax return, and for sellers building lists of billing companies. It covers the right code, how coding, practice management and collections change it, the SIC equivalent, size standards and the HIPAA definitions that shape how these firms buy.

The medical billing code: 541219

NAICS has no medical billing code, so the Census Bureau's index is the authority. It lists "billing services" under 541219, Other Accounting Services, along with "medical coding services combined with accounting services (except CPA services)." The definition says 541219 covers establishments other than CPA offices that provide accounting services, and names "accountant (except CPA) offices, bookkeeper offices, and billing offices."

So a company that submits claims, posts payments, works denials and reports receivables for physician practices, hospitals or labs is 541219. The type of client doesn't matter: billing for a dental group, an ambulance service or a behavioral health clinic is the same code. What would move you is a change in the work itself.

Codes that fit related revenue cycle work

The coding and practice management rows come straight from the Census index: "medical coding services, not combined with accounting services" is listed under 561499, and "medical office management services" and "managing offices of physicians and surgeons" under 561110. The 561110 definition covers a "range of day-to-day office administrative services, such as financial planning; billing and recordkeeping; personnel," and its cross-reference sends firms providing "only one of the support services (e.g., accounting services)" to the code for that service. That's the line: billing alone is 541219, the whole back office is 561110.

The insurer side is separate. A company processing claims on behalf of a health plan or employer plan is a third party administrator (524292), not a billing company, even though both handle claims.

The SIC code for medical billing

Medical billing companies use SIC 8721, Accounting, Auditing, and Bookkeeping Services, whose "other accounting services" piece maps to 541219. The related SIC codes follow the same split as NAICS: 7389, Business Services, NEC, for coding-only firms (mapping to 561499), 8741, Management Services, for practice management (561110), and 7322, Adjustment and Collection Services, for collection agencies (561440).

SIC 8099, Health and Allied Services, NEC, sometimes suggested for medical billing, isn't right: it's a code for health services, and its NAICS equivalents are blood banks, family planning centers, medical artists and similar services. The SEC's list has no 8721; listed revenue cycle companies file under software or services codes.

How many medical billing companies there are

No federal count isolates medical billing. County Business Patterns counted 47,699 establishments in 541219 in 2023, with 250,400 employees and $15.1 billion in payroll, but that includes bookkeepers and other non-CPA accountants. The related codes:

These count locations with paid employees, on a NAICS 2017 basis; none of the four codes changed in 2022. Billers working alone from home aren't in them. The top states for 541219 are California (6,444), Florida (5,243), Texas (4,096), New York (3,279) and Illinois (1,759).

Where the code is used, and the HIPAA side

• Federal contracts. A solicitation for billing or revenue cycle services carries one NAICS code, chosen by the largest share of contract value (13 CFR 121.402). If an agency codes a coding-heavy contract as 561499, the $21.5 million standard applies, not 541219's $25.0 million. An interested party can appeal the code within 10 calendar days of the solicitation (13 CFR 121.1103).
• HIPAA. The privacy rule defines a business associate as anyone who handles protected health information on a covered entity's behalf for functions "including claims processing or administration ... billing, benefit management, practice management, and repricing," so billing companies sign business associate agreements with their clients. The rule also defines a health care clearinghouse to include "a billing service" that converts nonstandard claims data into standard transactions, or the reverse, which makes such a billing service a covered entity in its own right.
• Banks, insurers and tax returns. The IRS business activity list uses 541219 as is. Banks and insurers will group you with bookkeepers under 541219, so describe the medical work too.

Finding medical billing companies

Public pure plays are rare. Waystar Holding (SEC SIC 7373, Lehi, UT), which sells healthcare payment software, reported $1.10 billion in revenue for 2025 in its 10-K. R1 RCM, a revenue cycle management company, had its shares delisted in November 2024 (Form 25-NSE) and has filed no annual report since. Most billing companies are private and small. A Bebop search such as medical billing companies in Florida with 20 to 100 employees that serve orthopedic practices returns matching firms with the reason each fits. If you sell to the practices rather than the billers, the NPI Registry lists providers by specialty and location, and the guide to selling to hospitals covers how hospitals buy and who decides.

Worked example

Illustrative example. The company and figures are invented.

ClaimPath Revenue Services (claimpath.example) has 160 employees. Last year's $16.4 million in revenue came from end-to-end billing for physician groups (62%), coding-only contracts for two hospitals (23%) and collecting patient balances (15%).

Its primary code is 541219 (SIC 8721), with 561499 and 561440 as secondary codes in SAM.gov. It signs a business associate agreement with every client.

Its receipts over five years were $11.2 million, $12.9 million, $14.1 million, $15.4 million and $16.4 million: $70.0 million, an average of $14.0 million. That's small under 541219 ($25.0 million), 561499 ($21.5 million) and 561440 ($19.5 million). If it grows 20% a year, the average passes $19.5 million within about three years, and collection set-asides close to it first.

Next step: see how billing sits beside bookkeeping, CPA, tax and payroll firms in the NAICS codes for bookkeeping and accounting.