Laboratory Requirements (CLIA)
The US clinical-laboratory certification regime under the Clinical Laboratory Improvement Amendments of 1988 (CLIA), administered by CMS. Every laboratory testing human specimens for health assessment or the diagnosis, prevention, or treatment of disease must hold a CLIA certificate matched to its test complexity, meet quality-system, personnel, and proficiency-testing requirements, and stand inspection. CMS certifies the laboratory's operation; FDA separately regulates the tests and devices the laboratory uses — two different agencies, two different objects.
What this does not cover
stated in the document's own scope- CMS certifies the laboratory's operation; the tests, instruments, and reagents the laboratory uses are FDA's territory — device clearance and complexity categorisation are not CLIA functions.
- Covers testing of human specimens for clinical purposes; pure research testing that does not report patient-specific results falls outside CLIA.
- A US regime: internationally, medical-laboratory quality runs on ISO 15189 accreditation and national licensing, not CLIA certificates.
Always verify against the current published text before relying on it for a submission or inspection.
Overview
42 CFR Part 493 is the CLIA regulation — the certification regime that every United States laboratory testing human specimens for clinical purposes operates under. Administered by the Centers for Medicare & Medicaid Services, it ties a laboratory's certificate to the complexity of its testing: a certificate of waiver for waived tests, provider-performed microscopy, and certificates of compliance or accreditation for moderate- and high-complexity testing. Around that spine sit the operating requirements: successful proficiency testing for regulated analytes, quality systems spanning the pre-analytic, analytic, and post-analytic phases of the total testing process, personnel qualifications by role up to the laboratory director, and inspection by CMS, its agents, or an approved accreditation organisation.
Scope & applicability
All US facilities testing human specimens for clinical purposes — hospital labs, independent labs, physician-office labs, and clinical-trial testing performed on US specimens. Research testing that does not report patient-specific results is outside CLIA.
Legal basis & how it acquires force
Issued under the Clinical Laboratory Improvement Amendments of 1988 (42 U.S.C. 263a), which extended federal certification to essentially all clinical testing of human specimens. The consolidated regulations were published on 28 February 1992 and have been amended since, including proficiency-testing updates finalised in 2022. CMS administers the program with the CDC (scientific and technical support) and FDA (test complexity categorisation) — and the division of labour matters: CMS certifies the laboratory's operation, while FDA regulates the tests and devices themselves.
Document structure
| Part | Covers |
|---|---|
| General provisions and applicability | Which laboratories need a certificate and the definitions the part runs on |
| Certificates | The certificate types — waiver, provider-performed microscopy, registration, compliance, accreditation — and their conditions |
| Proficiency testing | Enrolment, successful participation for regulated analytes, and the prohibition on PT referral |
| Quality systems | Requirements across the pre-analytic, analytic, and post-analytic phases of the total testing process |
| Personnel | Qualifications and responsibilities by role, including the laboratory director |
| Inspections and enforcement | Survey by CMS or approved accreditation organisations, and the sanctions framework |
Key requirements
- A CLIA certificate appropriate to test complexity: waiver, provider-performed microscopy, compliance, or accreditation
- Successful proficiency testing for regulated analytes, with referral of PT samples to another lab prohibited
- Quality systems across the total testing process — pre-analytic, analytic, and post-analytic
- Personnel qualifications by role, including laboratory director responsibilities
- Inspection by CMS, its agents, or a CMS-approved accreditation organisation
Implementation tips
- Sponsors placing trial testing in US labs should verify the certificate type and scope match the testing performed — a certificate of waiver does not cover non-waived trial assays, and PT referral violations carry severe sanctions
Revision notes
The consolidated CLIA regulations were published 28 February 1992 and have been amended repeatedly since — including proficiency-testing updates (2022) and periodic personnel and fee revisions.
Where this control fails
live FDA enforcementLive FDA recalls SPEQ maps to this standard’s topics — a SPEQ interpretation, not an FDA classification.
International alignment
CLIA is the US member of the clinical-laboratory quality family: ISO 15189 is the international accreditation standard for medical laboratories (CMS-approved accreditation organisations map their programmes onto CLIA requirements), ISO/IEC 17025 serves testing laboratories generally, and WHO GCLP guides clinical-trial laboratories in globally distributed studies. For trials with US specimens, CLIA certification of the testing laboratory is the operative requirement — a fact GCP quality systems must capture.
42 CFR Part 493: frequently asked questions
Quick answers to common questions about 42 CFR Part 493.
Who needs a CLIA certificate?
Any US facility testing human specimens for health assessment or the diagnosis, prevention, or treatment of disease — hospital, independent, and physician-office laboratories alike. The certificate type must match the complexity of the testing performed, from waived tests through high-complexity work.
What is the difference between CMS's and FDA's roles in lab testing?
CMS runs CLIA: it certifies and inspects the laboratory's operation. FDA regulates the products: it clears or approves the tests and instruments and categorises their complexity. A laboratory question (personnel, QC, PT) is CLIA; a test question (clearance, labelling) is FDA.
What is proficiency testing under CLIA?
External challenge samples the laboratory must test and report for its regulated analytes, with performance scored against defined criteria. Referring a PT sample to another laboratory is prohibited and carries some of the regime's severest sanctions.
How does CLIA relate to ISO 15189?
ISO 15189 is the international medical-laboratory accreditation standard; CLIA is US law. CMS-approved accreditation organisations bridge them — a lab may hold a certificate of accreditation through a programme whose requirements meet or exceed CLIA's — but for US testing the CLIA certificate is what the law requires.
This standard in practice
Recall domain is a SPEQ mapping of this standard’s topics, not an FDA classification.