Proficiency Testing (PT)

6042 - Proficiency Testing (PT) (Rev. 230; Issued: 07-11-25; Effective: 07-11-25; Implementation: 07-11-25) 42 CFR Part 493 Subpart H, Participation in Proficiency Testing for Laboratories Performing Non-waived Testing, provides laboratories with the PT requirements they must follow to comply with CLIA. The subpart specifies requirements for PT enrollment, testing, PT sample handling, and documentation. The prohibition of referral of PT samples to another laboratory is found at 42 CFR 493.801(b)(4) and, if identified, carries one of the most severe sanctions in the CLIA law and regulations. The subpart also identifies successful participation in a CMS-approved PT program and how a laboratory may be reinstated when it has performed unsuccessfully. (Please see 42 CFR 493.2, Definitions, for unsatisfactory participation and unsuccessful participation.) NOTE: The referral to another laboratory of a sample from a PT program by ANY laboratory of ANY certificate type is considered PT referral. If a laboratory enrolls and participates in PT, regardless of certificate type, all rules related to PT referral apply. Notify CMS if PT referral is identified. For additional information on PT Referral, see section 6061. PT Program Approval: Not-for-profit organizations or States may apply to CMS to become a CMS-approved PT program for specific subspecialties and analytes. CMS PT specialists perform an in-depth review of applications submitted for approval to determine whether the program meets the requirement of 42 CFR Part 493 Subpart I. The CLIA statute requires annual review of approved programs. Annual re-approval reviews are also conducted by CMS specialists. Approved PT programs and the subspecialties and analytes for which they are approved are listed on the CMS CLIA Web site each year.