Fact sheet

Medicare Program: Clinical Laboratory Improvement Amendments of 1988 (CLIA) Proficiency Testing Regulations Related to Analytes and Acceptable Performance

Medicare Program:  Clinical Laboratory Improvement Amendments of 1988 (CLIA) Proficiency Testing Regulations Related to Analytes and Acceptable Performance

On February 1, 2019, the Centers for Medicare & Medicaid Services (CMS) and the Centers for Disease Control and Prevention (CDC) issued a Notice of Proposed Rulemaking [CMS-3355-P].  This notice of proposed rulemaking includes the addition and deletion of analytes requiring proficiency testing and updates  criteria for acceptable performance under the Clinical Laboratory Improvement Amendments of 1988 (CLIA).

This fact sheet discusses the changes that CMS and CDC are proposing to make:

For non-microbiology specialties and subspecialties, we are proposing to add 29 analytes to Subpart I of the CLIA regulations, based upon the following criteria: 

1.  Current availability of proficiency testing (PT) materials
2.  The number of proficiency testing programs that can provide analytes
3.  Volume of patient testing performed nationwide
4.  Impact on patient health and/or public health
5.  Cost and feasibility of implementation

For microbiology specialties and subspecialties, the proposed rule requires updates to specify broad categories of tests when proficiency testing is required to allow for flexibility of new technologies currently in use and those that may be developed in the future.

The proposed rule  amends regulations to reflect how  moderate and high complexity laboratories that are also performing waived tests are subject to compliance with PT referral requirements found at 42 CFR §493.801(b)(1) through (6).  This change is to align the regulations with the CLIA statute (42 U.S.C. 263a (i)(4)), allowing CMS to apply sanctions to those laboratories performing waived testing found participating in PT referral.

Additional Background:

There are 246,143 CLIA-certified laboratories, of which 36,777 are required to enroll in a CMS approved proficiency testing program and comply with the proficiency testing regulations.  CMS and CDC recognized that the proficiency testing regulations, created in 1992, required update.   The Clinical Laboratory Improvement Advisory Committee (CLIAC), the federal advisory committee charged with providing regulatory and laboratory quality advice to the CLIA program, made recommendations for proficiency testing that included the following:  

  • Updating the list of required proficiency testing analytes;
  • Revising scoring criteria for acceptable performance;
  • Updating requirements for microbiology to include broad categories of organisms rather than a list of specific organisms; and,
  • Clarification of requirements that address proficiency testing referral.

CMS and CDC collaborated to develop a scientifically sound, evidence-based process to revise the list of required proficiency testing analytes and determine the acceptable performance limits. 

Testing has evolved significantly since 1992 and technology is now more accurate and precise. In addition, many tests for analytes that were not originally included in the CLIA regulations are now in routine clinical use. For example, tests for cardiac markers such as troponins, used to diagnose heart attacks, and hemoglobin A1c, a test commonly used to monitor glycemic control in people with diabetes, were not routinely performed prior to 1992. Because these requirements were specified in regulation, rulemaking is required to update them.

CMS encourages public and other stakeholder comments, questions, or thoughts on this notice of proposed rulemaking. The notice of proposed rulemaking can be downloaded from the Federal Register at: