Pediatric Coding Alert

Question: When and how should we use the -QW modifier for lab tests? Our lab does provider-performed microscopies (PPM) and strep, mono, and urine pregnancy kit testing.

Arizona Subscriber

Answer: To report your services to the payer, your lab needs to be certified under the Clinical Laboratory Improvement Amendments (CLIA) of 1988. Medicare has a list of lab tests that fall into various categories. Most commonly, in physicians offices, the lab tests fall into the waived category, which means they perform tests that pose little or no risk to their patients. If lab tests are performed that do not fall into this category, the lab must apply for varying levels of CLIA certification, other than waived. This list of waived lab tests contains not only the tests that have been designated as waived but also the specific brand name and manufacturer of the approved types of tests.

The -QW modifier (CLIA waived test) identifies to the payer that your lab is performing a waived lab test, suggesting that you have met all of the requirements necessary. The -QW modifier should be appended to the CPT code for the specific test ordered and performed.