Know How Modifier QW Can Affect Your Reimbursement

Published on Tue Mar 03, 2015 PDF

Quick refresher on QW criteria. 

Modifier QW (CLIA waived test) is an informational HCPCS modifier appended to lab service codes that are on the CLIA waived test list. Remember these points when considering whether to include modifier QW on your claim: 

• Modifier QW does not change your reimbursement.

• It does attest that the practice recognizes that it can only perform tests with the "waived" designation and that the kit used to test the specimen was FDA classified as CLIA waived. Do not bill with modifier QW if you haven't verified that the test was performed with a CLIA waived kit.  

• The method of lab test plays the key role in whether you should report modifier QW. Labs with a CLIA certificate of waiver should bill G0434 with modifier QW. Labs with a CLIA certificate of compliance or accreditation can perform non-waived tests and should not append modifier QW.  

• Medicare lab tests claims can be denied if you do not report modifier QW and the lab test code requires that the provider uses only a CLIA waived test kit. 

• Not all payers require modifier QW. Be sure to verify whether any non-Medicare payers want the modifier on applicable claims.