Powered by Oracle® RightNow

Modifier QW Fact Sheet


CLIA waived test

Appropriate Usage:

  • Any test on the CMS list that CLIA standards are waived for

Inappropriate Usage:

  • Any code that is not on the CLIA waived test list

The Clinical Laboratory Improvement Amendments (CLIA) of 1988 requires all laboratory testing sites to have one of the following certificates to legally perform clinical laboratory testing:

  • Certificate of Waiver
  • Certificate of Registration
  • Certificate of Accreditation
  • Certificate for Physician-Performed Microscopy

Certain CLIA Certificates that have been issued may limit the holder to perform only certain tests. There are only two types of CLIA certificates that limit holders to certain test procedures:

  • Certificate of Waiver
  • Certificate of Physician Performed Microscopy Procedures (PPMP)

If a service is denied as not covered under your CLIA certificate, you may not bill the beneficiary for the service.

If a provider currently has one Medicare Part B provider number covering more than one clinical lab testing site (e.g., an office on Main Street and an office on Oak Street), both sites require a CLIA number. The provider should use the CLIA number that specifically represents the site where the test(s) was/were performed.

  • All clinical diagnostic laboratories must include their CLIA numbers on all claims to avoid an unprocessable rejection. The CLIA number must be placed in Item 23 of the CMS-1500 claim form. Electronic submitters using the ANSI X12 4010 version should use segment 2-180-REF02 (X4).
  • Please note: A CLIA Waived Test still requires the provider to include their CLIA number on the claim.
  • To be recognized as a waived test, some CLIA waived tests have unique HCPCS procedure codes and some must have a QW modifier included with the HCPCS code. To view the CMS CLIA waived test list, refer to CMS Internet Only Manual (IOM), Publication 100-04, Chapter 16, Section 70.8 (see link listed below).

CMS Resources

CMS CLIA webpage

CMS CLIA waived test list