Pathology/Lab Coding Alert

Question: I can't find modifier QW in the CPT manual , but I've been told we should use it for billing lab tests. What is it, and when should we use it?


Tennessee Subscriber
 

Answer: You won't find modifier QW (CLIA waived test) in the CPT manual because it is a HCPCS Level II modifier. You should append the modifier to most approved lab test codes if you bill for a laboratory that operates under a certificate of waiver.

The Clinical Laboratory Improvement Amendments (CLIA) regulations require labs to be certified for a specific complexity of lab tests. Labs with a certificate of waiver perform only simple tests that involve little risk of error.

Do this: Medicare edits lab tests at the CLIA certification level. If you bill for a CLIA-waived lab, you can only report CLIA-waived tests, and you must append modifier QW to the code, in most cases. If you don't use the modifier, you won't get paid for the test.

Exception: The following tests do not require modifier QW to pass the edits: 82270, 82272 and G0107 (Fecal occult blood tests); 81002 (Urinalysis ... non-automated, without microscopy), 81025 (Urine pregnancy test, by visual color comparison methods), 82962 (Home-use blood glucose monitoring device), 83026 (Hemoglobin; by copper sulfate method, non-automated), 84830 (Ovulation tests, by visual color comparison ...), 85013 (Blood count; spun microhematocrit), and 85651 (Sedimentation rate, erythrocyte; non-automated).

Don't miss: You must put your CLIA number on the claim form.

CMS provides quarterly updates that add any newly approved tests to the complete list of waived-status tests. You can view the most recent update on the Internet at www.cms.hhs.gov/transmittals/downloads/R872CP.pdf.