What Is ANAB? ANSI National Accreditation Board Explained

What ANAB is

ANAB (the ANSI National Accreditation Board) is a US-based laboratory and certification-body accreditor operated as a subsidiary of the American National Standards Institute (ANSI). It was formed in 2011 through the consolidation of the ANSI-ASQ National Accreditation Board (a joint venture ANSI had run with the American Society for Quality since 2007) and ACLASS, an earlier ANSI-owned laboratory accreditation program. ANAB itself does not perform testing, calibration, or inspection work — it audits and formally recognizes that another organization’s laboratory, inspection body, or certification program meets an internationally recognized competence standard.

What ANAB accredits, and against which standards

ANAB operates accreditation programs across several distinct ISO/IEC standards, each covering a different kind of conformity-assessment body:

• Testing and calibration laboratories — ISO/IEC 17025, the general requirement for the competence of testing and calibration labs. This is the scope most relevant to procurement teams sourcing analytical, environmental, materials, or contract testing services.
• Medical laboratories — ISO 15189, covering quality and competence in clinical testing.
• Inspection bodies — ISO/IEC 17020.
• Reference material producers — ISO 17034.
• Biobanks and biorepositories — ISO 20387 (see CASRAI’s ISO 20387 entry for what that standard specifically requires).
• Proficiency testing providers — ISO/IEC 17043.
• Management-system, product, and personnel certification bodies — ISO/IEC 17021-1, 17065, and 17024 respectively. This is the accreditation that sits behind a vendor’s ISO 9001, ISO 13485, or ISO 27001 certificate.

ANAB is a full signatory to the ILAC Mutual Recognition Arrangement (for laboratory and inspection accreditation) and the IAF Multilateral Recognition Arrangement (for management-system and product certification). In practice, this is what makes an ANAB-accredited test report or certificate portable: a signatory-to-signatory arrangement is the mechanism that lets accepting parties in other countries rely on the result without re-testing.

Why this matters when evaluating a lab or vendor

For a lab manager, procurement officer, or research administrator, “ANAB-accredited” is a specific, checkable claim, not a marketing phrase. It tells you a vendor’s technical competence in a defined scope has been independently audited against a named ISO/IEC standard, on a recurring surveillance cycle, by a third party that is itself subject to peer evaluation through ILAC/IAF. That is meaningfully different from a vendor simply asserting it follows “ISO methods” or displaying an ISO logo without naming an accreditor.

The practical procurement question is almost never “is this vendor accredited?” in the abstract — it is “is this vendor accredited, by whom, to which standard, and does the scope of accreditation actually cover the specific test method, matrix, or service I’m buying?” ANAB accreditation is issued against a defined scope document, not a blanket statement of competence, and vendors are commonly accredited for some methods or programs but not others.

How to verify an ANAB accreditation before you contract

ANAB publishes a searchable public directory of accredited organizations at anab.org, and each listing links to a current scope of accreditation — the actual document listing which standards, test methods, matrices, or certification programs that organization is accredited for, and the accreditation’s effective and expiration dates. Before relying on an accreditation claim in a bid, quote, or vendor qualification file:

• Confirm the organization appears in ANAB’s current directory under the legal entity name on the quote or contract, not just a parent-company or brand name.
• Open the scope of accreditation and confirm the specific test method, standard, or program you need is actually listed — not just the accreditation as a whole.
• Check the certificate/scope expiration and any recent suspension or scope-reduction history where the directory shows it.
• If the vendor cites a different accreditor entirely (A2LA, PJLA, and others also accredit US labs to ISO/IEC 17025), confirm that body is itself an ILAC MRA signatory rather than assuming equivalence.

ANAB accreditation vs. certification — a common procurement mix-up

Accreditation and certification are frequently used interchangeably in vendor marketing, but they are different scopes of assurance. A laboratory being ANAB-accredited to ISO/IEC 17025 means its technical testing competence in a specific scope has been audited. A company being ISO 9001 certified (even by an ANAB-accredited certification body) means its quality management system has been audited — a broader, process-level claim that says nothing on its own about the technical validity of a specific test result. A vendor can legitimately hold one without the other. Procurement due diligence for a testing or calibration service should look for the laboratory-level ISO/IEC 17025 accreditation specifically, not settle for a corporate ISO 9001 certificate as a substitute.

Worked example

A biotech company sourcing a contract laboratory for pesticide-residue or cannabis-potency testing (see CASRAI’s pesticide residue testing buying guide and cannabis pesticide testing guide) should ask the shortlisted labs for their ANAB (or other ILAC MRA-signatory) accreditation certificate number, then verify directly in the accreditor’s public directory that the specific analytes and matrices being purchased are within the lab’s listed scope — rather than accepting a general claim of being “ISO 17025 accredited” at face value.

Counter-example

A supplier’s website stating it is “ISO certified” with no named accreditor, no certificate number, and no published scope is not a verifiable accreditation claim in the sense described above — it cannot be checked against ANAB’s or any other accreditor’s public directory, and procurement should treat it as unverified until the supplier provides the specific accreditor, certificate number, and scope.

ANAB and CLIA

In the US, clinical laboratories that test human specimens for the diagnosis, prevention, or treatment of disease must hold a CLIA certificate issued under the Clinical Laboratory Improvement Amendments program administered by CMS. ANAB’s ISO 15189 medical-laboratory accreditation is a separate, internationally recognized quality standard that a clinical lab may hold voluntarily alongside its CLIA certification; it is not itself a form of CLIA certification. Procurement or compliance staff evaluating a clinical reference laboratory should confirm CLIA certificate status separately from any ISO 15189/ANAB accreditation the lab advertises.

Related terms

• ISO 20387 (Biobanking)
• CAP Biorepository Accreditation Program (CAP-BAP)
• NELAC (National Environmental Laboratory Accreditation Conference)
• Second-Party Audit