The Centers for Medicare and Medicaid Services (CMS) require that all non-waived testing laboratories participate in Proficiency Testing (PT). PT is defined as the testing of unknown samples sent to a laboratory by a CMS-approved PT provider program_[1]. PT is an important tool that the laboratory can use to verify the accuracy and reliability of its patient testing. Routine reviews of PT reports by the laboratory staff and the laboratory director will alert them to areas of testing that are not performing as expected, as well as indicate subtle shifts and trends that, over time, would affect their patient results and ultimately, patient care.

PT is required for only the limited number of tests found in Subpart I, Proficiency Testing Programs for Non-Waived Testing_[2], of the CLIA regulations. If your laboratory performs any of the tests found in Subpart I, you must perform PT on each of the tests. 

We refer to the tests listed in Subpart I as "regulated" analytes. Review the specialty, subspecialty, and analytes listed and determine which specialties, subspecialties, and analytes you perform in your laboratory. A list of "regulated" analytes is available on pages 10-11 of CLIA Brochure #8 - Proficiency Testing_[3].

Most sets of PT samples are sent to participating laboratories three times per year, referred to as PT events. After testing these unknown samples, the laboratory reports its unknown sample results back to the PT provider program. The program grades the results using the CLIA grading criteria and sends the laboratory scores reflecting how accurately it performed the testing.