Pathology/Lab Coding Alert

Question: Please help settle a disagreement in our office — as a lab with a CLIA certificate of compliance, not a CLIA certificate of waiver, do we need to use modifier QW on lab tests?

Texas Subscriber

Answer: No, you don’t have to use modifier QW (CLIA waived test) if you’re operating under a CLIA certificate of compliance.

The certificate of compliance means that your lab is approved to perform lab tests that are CLIA waived, moderate-complexity, and/or high-complexity, and that your lab has passed inspection.

Labs that have a certificate of waiver are approved to perform only CLIA-waived tests. As such, these labs must append modifier QW to attest that the test they’re billing for is indeed CLIA waived. 

QW facts: Modifier QW 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.
• QW attests that the reporting lab can only perform tests with the waived designation, and that the kit used to test the specimen was FDA classified as CLIA waived. CLIA-waived labs should not bill with modifier QW if they haven’t verified that the test involved a CLIA waived kit.
• Labs with a CLIA certificate of waiver should bill appropriate tests with modifier QW; labs with a CLIA certificate of compliance or accreditation can perform non-waived tests and should not append modifier QW.
• Not all payers require modifier QW. Be sure to verify whether any non-Medicare payers want the modifier on applicable claims.