Use of HCPCS Modifiers GA, GX, GY and GZ in MA Billing

CMS allows Medicare Advantage plans to establish billing and payment rules that may differ from Original Medicare. For more details, refer to Section 10.2, Chapter 4 of the Medicare Managed Care Manual. 

The purpose of this policy is to provide clear and compliant billing guidance for the use of HCPCS Modifiers GA, GX, GY and GZ when submitting claims to BCBSNE Medicare Advantage, ensuring proper assignment and adherence to plan-specific rules. Providers must notify Medicare Advantage members of non-coverage and follow these billing guidelines: 

Modifier GA - Pre-Service Notice of Non-Coverage Provided or Waiver of Liability Statement on File
Use when: 

• When an item or service is anticipated to be denied due to lack of medical necessity, and a properly completed ABN is on file. 
• It may be appended to either a specific or miscellaneous HCPCs code. 

Outcome: 

• If billed with a GA modifier, the claim goes to patient liability. You may bill the member. 
• If a non-covered service is billed without a GA modifier, BCBSNE will deny the claim. It will go to provider liability. 

Modifier GZ - Service Not Covered by Medicare 
Use when: 

• The service is expected to be denied as not reasonable or necessary. 
• No advance notice of non-coverage was given to the member. 

Outcome: 

• Claim goes to provider liability. You may not bill the member.  

Modifier GX - Not Needed 
Modifier GX is not required for services that are statutorily non-covered or do not meet the definition of a Medicare benefit. 

Use When: 

• When services are submitted with non-covered charges only. 
• May be reported in combination with GY modifier. 

Outcome: 

• If a non-covered service is billed with a GX modifier, BCBSNE will deny the claim. It will go to provider liability. 

Modifier GY - Statutorily Excluded Services 
Use when: 

• The item/service is excluded by statue and does not qualify as a Medicare benefit. 

Outcome: 

• If billed with a GY modifier, the claim goes to patient liability. You may bill the member.