The Centers for Medicare & Medicaid Services (CMS) regulates all laboratory testing (except research) performed on humans in the U.S. through the Clinical Laboratory Improvement Amendments (CLIA).

For more information about CMS regulations and CLIA, visit the CMS website.

Proficiency Testing

A vital component of quality assessment for laboratory is Proficiency Testing.

For more information on Proficiency Testing, read the CLIA Brochure #8 - Proficiency Testing DO's and DON'Ts - "Blue Book".

What is Proficiency Testing?

Testing of unknown samples sent to a laboratory by a CMS approved PT program After testing the PT samples in the same manner as its patient specimens, the laboratory reports its sample results back to their PT program. The program grades the results using the CLIA grading criteria. The laboratory received scores reflecting how accurately it performed the testing. CMS and accreditation organizations routinely monitor their laboratories’ performance.

  • NEVER discuss your PT results with another laboratory.
  • NEVER enter into discussion with another laboratory about their PT results before the PT event cut-off date.
  • NEVER send your PT samples to another laboratory even if you send your patient specimens to another laboratory for confirmation or identification testing.

For questions please contact laboratory compliance at