Quick Facts

Status

GX

Modifier GX

Notice of Liability Issued, Voluntary Under Payer Policy

Active

Global Period

Not Applicable

Modifier

GX

Applies To

Statutorily Excluded or Non-Covered Services

Category

Use With

Medicare

CPT & HCPCS Codes

What is Modifier GX?

Modifier GX indicates that a voluntary Advance Beneficiary Notice of Noncoverage was issued before providing a service for which Medicare does not require a notice. It is generally used when denial is expected for a reason other than medical necessity, such as a statutory exclusion or lack of a Medicare benefit category.

Modifier GX may be reported by itself in certain circumstances or with Modifier GY when the service is statutorily excluded from Medicare coverage.

When to Use

  • A voluntary notice of potential financial responsibility was issued.

  • Medicare does not require an ABN for the service.

  • The service is excluded from Medicare coverage.

  • Denial is expected for a reason other than medical necessity.

  • The patient was informed of possible financial responsibility before receiving the service.

Documentation Requirements

  • Maintain the voluntary notice in the patient’s record.

  • Document when the notice was provided.

  • Describe the service being provided.

  • Explain why Medicare coverage is not expected.

  • Record the patient’s acknowledgment when applicable.

Examples
Example 1

A patient requests a service that is statutorily excluded from Medicare coverage. The provider voluntarily gives the patient a written notice explaining the expected denial before providing the service. Modifier GX may be reported with Modifier GY.

Example 2

A provider offers a service that does not meet the definition of a Medicare benefit. The patient receives a voluntary notice and chooses to proceed with the service.

Billing Tips

  • Use Modifier GX only when a voluntary notice was issued.

  • Obtain the notice before providing the service.

  • Modifier GX is commonly paired with Modifier GY for statutorily excluded services.

  • Do not use GX for an expected medical-necessity denial requiring Modifier GA or GZ.

  • Verify Medicare and payer-specific claim requirements.

Common Billing Mistakes

  • Reporting GX when no voluntary notice was issued.

  • Using GX for a medical-necessity denial.

  • Confusing GX with Modifier GA.

  • Failing to maintain the notice in the patient’s record.

  • Using the wrong modifier combination.

Related Modifiers
Modifier GA

Waiver of Liability Statement Issued

Modifier GY

Statutorily Excluded Service

Modifier GZ

Expected Denial Without an ABN

Additional Resources

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