How to Verify a Medical Technologist / Clinical Lab Scientist Credential

MT vs. MLS: title history

“Medical Technologist” (MT) is the historical title for this profession. The American Society for Clinical Pathology (ASCP) renamed the credential to “Medical Laboratory Scientist” (MLS) in 2009 to better reflect the scope of practice. Older practitioners may hold the MT(ASCP) credential; those certified after 2009 hold MLS(ASCP).

Both MT(ASCP) and MLS(ASCP) are equivalent and interchangeable for employment purposes. When verifying credentials, either designation is acceptable for a senior laboratory scientist role.

ASCP Board of Certification

The ASCP Board of Certification (BOC) is the primary credentialing body for clinical laboratory professionals in the United States. The MLS(ASCP) credential requires a bachelor's degree in medical laboratory science (or equivalent) from a NAACLS-accredited program and passage of the ASCP MLS certification examination.

To verify ASCP certification:

1. Go to ascp.org
2. Navigate to “Verify a Certificate” or the BOC credential lookup
3. Search by name or certificate number
4. Confirm: credential type (MT or MLS), Active certification status, and expiration
5. Note any disciplinary actions associated with the certificate

Other lab science credentialing bodies

ASCP is the most widely recognized, but other credentialing bodies also certify medical technologists and laboratory scientists:

• AMT (American Medical Technologists): Issues the MT(AMT) credential. Verifiable at americanmedtech.org.
• AAB (American Association of Bioanalysts): Issues CLSp(MB) and related specialty credentials. Used primarily for physician office laboratories.
• NCA (National Credentialing Agency): Previously issued CLS(NCA) credentials; NCA merged into ASCP in 2009. Older NCA credentials are recognized but no longer renewed through NCA.

For hospital and reference laboratory roles, ASCP is the standard. For physician office labs or smaller facilities, AMT may be accepted. Confirm the employer's accepted credentialing bodies before evaluating an applicant's credentials.

State lab personnel licensure

A subset of states require laboratory personnel to hold a state license or registration in addition to national certification. States with clinical laboratory personnel licensure requirements include California (CLS license through CDPH), New York, Florida, Hawaii, Nevada, and others.

In California, clinical laboratory scientists (CLS) must hold a California CLS license issued by the California Department of Public Health (CDPH), regardless of ASCP or AMT certification status. The California CLS license is verified through the CDPH Lab Field Services license lookup.

For states without specific lab personnel licensure, the national ASCP or AMT credential combined with CLIA compliance is the operative standard.

CLIA requirements

The Clinical Laboratory Improvement Amendments (CLIA) set federal standards for laboratory testing personnel. CLIA defines complexity levels (waived, moderate complexity, high complexity) and specifies the education and training requirements for testing personnel at each level.

For high-complexity testing, CLIA requires testing personnel to have specific education and training that MLS(ASCP) credentials satisfy. When hiring for CLIA-regulated laboratories, confirm that the credential level meets the testing complexity level of the specific laboratory.

Red flags

• No ASCP certification or expired CMP certification (3-year cycle)
• No state license in a state requiring lab personnel licensure (CA, NY, FL, HI, NV)
• Presenting MLT(ASCP) — medical laboratory technician — as equivalent to MLS(ASCP) for scientist-level roles
• Degree from a non-NAACLS-accredited MLS program
• ASCP credential type does not match the specialty required (e.g., BB for blood bank roles)

Verification checklist