Quick Facts

Status

GZ

Modifier GZ

Item or Service Expected to Be Denied as Not Reasonable and Necessary

Active

Global Period

Not Applicable

Modifier

GZ

Applies To

Expected Medical-Necessity Denials

Category

Use With

Medicare

CPT & HCPCS Codes

What is Modifier GZ?

Modifier GZ indicates that a provider expects Medicare to deny an item or service as not reasonable and necessary and that no valid Advance Beneficiary Notice of Noncoverage was obtained before the service was provided.

Because no valid ABN is on file, the provider generally cannot transfer financial responsibility for the denied service to the beneficiary.

When to Use

  • Medicare denial is expected because the service may not be medically necessary.

  • No valid ABN was obtained before providing the service.

  • The claim must still be submitted to Medicare.

  • The provider expects Medicare to deny payment.

  • The service is not statutorily excluded but may fail coverage requirements.

Documentation Requirements

  • Document the service provided.

  • Include the applicable diagnosis and clinical circumstances.

  • Maintain the physician order when required.

  • Support the reason the service was performed.

  • Document that no valid ABN was obtained.

Examples
Example 1

A diagnostic test is performed even though Medicare coverage criteria are not met. No ABN was obtained before the test, so the provider reports Modifier GZ.

Example 2

A provider expects Medicare to deny a service as not reasonable and necessary but must still submit the claim. Because no valid ABN is on file, Modifier GZ is appended.

Billing Tips

  • Use GZ when a medical-necessity denial is expected and no valid ABN exists.

  • Use Modifier GA instead when a valid ABN is on file.

  • Do not use GZ for services that are statutorily excluded from Medicare.

  • The beneficiary generally cannot be held financially responsible when GZ applies.

  • Review the applicable Medicare coverage policy before submitting the claim.

Common Billing Mistakes

  • Reporting GZ when a valid ABN was obtained.

  • Using GZ for a statutorily excluded service.

  • Confusing GZ with Modifier GA.

  • Failing to document the anticipated medical-necessity denial.

  • Attempting to bill the beneficiary despite the lack of a valid ABN.

Related Modifiers
Modifier GA

Waiver of Liability Statement Issued

Modifier GX

Voluntary Notice of Liability Issued

Modifier GY

Statutorily Excluded Service

Additional Resources

CPTCodeGuide provides a concise reference for Modifier GZ. For detailed Medicare billing guidance, documentation requirements, examples, denial scenarios, and modifier comparisons, visit ModifierLookup.com for the complete Modifier GZ guide.