Modifier QW- CLIA Waived Test

Modifier QW is used to identify Clinical Laboratory Improvement Amendments (CLIA) waived laboratory tests.

What is Modifier QW?

Modifier QW tells insurance payers that a laboratory test is CLIA waived and meets federal requirements for simplified laboratory testing.

When to Use Modifier QW

• A CLIA-waived laboratory test is performed
• The CPT code requires Modifier QW
• The testing facility has a valid CLIA certificate
• Documentation supports the laboratory service

Billing Example

A physician's office performs a CLIA-waived rapid influenza test. Modifier QW may be appended to the appropriate CPT code when required by payer guidelines.

Documentation Tips

• Document the laboratory test performed
• Verify the facility's CLIA certification
• Record test results in the medical record
• Follow payer-specific billing requirements

Common Denial Reasons

• Missing CLIA certification
• Modifier not required for the CPT code
• Incorrect modifier usage
• Incomplete laboratory documentation

Related Modifiers

Modifier GX

Modifier GA

Modifier GY