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Short answer: A CLIA number is the ten-character alphanumeric identification number CMS assigns to a laboratory location. You can check a laboratory’s CLIA certification and survey status, free of charge, in the CMS QCOR “CLIA Laboratory Lookup”. The number alone proves little; the certificate type and the location it covers are what tell you which testing the laboratory is allowed to perform.
This guide is general regulatory information for laboratory, clinic and procurement staff. It is not legal or medical advice.
Definition and scope
CMS describes the CLIA identification number as a “unique ten-character alpha-numeric” number. Per the CMS State Operations Manual (Chapter 6, section 6008), it is issued by the CLIA Data System when the application is first entered, and it is shown under the CMS Certification Number (CCN) column in some CMS data systems. Laboratories that are CLIA-exempt, and VA laboratories, hold no CLIA certificate but are still assigned a CLIA identification number, so a number by itself does not mean a certificate exists.
For what each certificate type requires and how complexity levels work, see CLIA certification and CLIA high-complexity testing requirements. This page covers the narrower task of reading a lookup result.
How to read the ten characters
The State Operations Manual breaks the number into three fields:
- Positions 1-2: the state in which the laboratory was located when it first applied for a CLIA certificate. A laboratory that later moves to another state keeps its original number, so the state prefix can differ from the laboratory’s current state.
- Position 3: the letter “D”, identifying a laboratory certified under CLIA.
- Positions 4-10: the unique facility identifier.
The number follows a laboratory location. Under 42 CFR 493.43, a laboratory performing nonwaived testing files a separate application for each laboratory location, with exceptions such as mobile or temporary laboratories that may be covered by the primary site’s certificate. A health system with several sites should therefore expect several numbers, not one.
How to look up a CLIA number with CMS
CMS points laboratories to the QCOR “CLIA Laboratory Lookup” to “check your laboratory’s certification and survey status for free, anytime” and to find laboratory demographic information. When you contact a State Agency or Accreditation Organization about a laboratory, CMS asks that you include the laboratory’s name and CLIA ID. Accredited laboratories direct questions to their Accreditation Organization.
CMS no longer mails paper certificates or fee coupons; the ID arrives in a fee notification email before payment and the certificate is emailed after payment. A laboratory asked for its certificate will therefore normally send an electronic copy.
What the certificate type tells you
The certificate type, not the number, sets the scope of testing. These definitions come from 42 CFR 493.2:
| Certificate type | What the regulation says |
|---|---|
| Certificate of waiver | The laboratory may perform only the waived tests listed at 42 CFR 493.15(c). |
| Certificate for provider-performed microscopy (PPM) procedures | For a laboratory where a physician, midlevel practitioner or dentist performs no tests other than PPM procedures (plus certain waived tests). |
| Registration certificate | Enables the entity to conduct moderate or high complexity testing, or both, until a survey determines compliance. |
| Certificate of compliance | Issued after an inspection finds the laboratory in compliance. |
| Certificate of accreditation | Issued on the basis of the laboratory’s accreditation by an accreditation organization approved by CMS. |
CMS’s own guidance for applicants is to apply for the certificate matching “the highest level of test complexity your facility performs”, on Form CMS-116 sent to the State Agency (New York and Washington follow separate processes). For waived testing, see CLIA-waived test.
Where lookups matter for labs, clinics and supply decisions
A verification checklist for checking a reference laboratory or testing partner’s documents:
- Match the identity. Compare the laboratory name and address on the certificate or contract with the lookup result for the CLIA number given. Remember the number tracks a location (42 CFR 493.43).
- Match the certificate type to the testing claimed. A certificate of waiver covers only waived tests; moderate or high complexity testing needs one of the other certificate types in the table.
- Read the type, not the prefix. The first two characters show the original application state, not necessarily today’s location.
- Ask for the certificate itself. It is delivered by email, so an electronic copy is the normal form.
- Route accredited laboratories correctly. If the laboratory holds a certificate of accreditation, its Accreditation Organization is the contact for accreditation questions.
The same checks fit supplier files; see supplier audits and vendor qualification. For how CLIA relates to voluntary accreditation, see ISO 15189 vs CLIA.
Common misunderstandings
“A valid-looking number means the laboratory is certified”
No. CLIA-exempt and VA laboratories hold numbers without a CLIA certificate (State Operations Manual, section 6008). Check the certificate type in the lookup.
“The state letters show where the laboratory is now”
Not necessarily. They show the state of the original application; a relocated laboratory keeps its number. The State Operations Manual adds that a laboratory keeps its number even if it withdraws from CLIA or changes certificate type, ownership or name, and that a number is not reassigned to another laboratory.
“One number covers a whole organization”
Generally the number belongs to a laboratory location, with the limited exceptions in 42 CFR 493.43.
FAQ
What is a CLIA number?
A ten-character alphanumeric identification number assigned by CMS to a laboratory under the Clinical Laboratory Improvement Amendments program.
Where do I look up a CLIA number?
In the CMS QCOR “CLIA Laboratory Lookup”, which CMS describes as free to use for checking certification and survey status.
Can a laboratory have more than one CLIA number?
Yes. A laboratory performing nonwaived testing files a separate application for each location, so multi-site organizations can hold several numbers.
What does the third character mean?
It is the letter “D”, which identifies a laboratory certified under CLIA.
Does a CLIA number tell me which tests a laboratory can run?
No. The certificate type determines that scope; a certificate of waiver, for example, allows only the waived tests listed at 42 CFR 493.15(c).
Sources
- CMS, State Operations Manual Chapter 6, section 6008 (Rev. 230, issued 07-11-25), checked 2026-11-01: https://www.cms.gov/regulations-and-guidance/guidance/manuals/downloads/som107c06pdf.pdf
- CMS, Apply for a CLIA Certificate, checked 2026-11-01: https://www.cms.gov/medicare/health-safety-standards/clinical-laboratory-improvement-amendments-clia/getting-started-clia/apply-clia-certificate
- CMS, Clinical Laboratory Improvement Amendments program page, checked 2026-11-01: https://www.cms.gov/medicare/quality/clinical-laboratory-improvement-amendments
- CMS QCOR, CLIA Laboratory Lookup, checked 2026-11-01: https://qcor.cms.gov/main.jsp
- 42 CFR 493.2, definitions, checked 2026-11-01: https://www.law.cornell.edu/cfr/text/42/493.2
- 42 CFR 493.43, application for registration certificate, certificate for PPM procedures, certificate of waiver, or certificate of accreditation, checked 2026-11-01: https://www.law.cornell.edu/cfr/text/42/493.43
