We are using the ABN for non-covered services (such as therapy codes) when the patient is under active care. We are also using the ABN for CMT codes when the patient is under maintenance care. We are now confused about when to use the modifiers GA & GY when billing CMT & therapy codes. Would you please explain when & why each should be used for Active and Maintenance Care?
GA is only permitted to be used on "covered but not payable procedures" which is only 98940-98942. This is the modifier you would append to these services when the patient has transitioned to maintenance care and Medicare will no longer reimburse.
To use this modifier, you must also have a signed ABN on file. Official description:
GA - WAIVER OF LIABILITY STATEMENT ISSUED AS REQUIRED BY PAYER POLICY, INDIVIDUAL CASE
The GY modifier indicates that the service is "statutorily excluded from Medicare benefit".
This modifier would be appended to all other services rendered in your practice (such as therapy codes, x-rays, exams, etc). This indicates that your practice is aware that Medicare will not reimburse for these services. You are not obligated to submit these statutorily non-covered services to Medicare but either way, you must code correctly. Official description:
GY - ITEM OR SERVICE STATUTORILY EXCLUDED OR DOES NOT MEET THE DEFINITION OF ANY MEDICARE BENEFIT
Because you are using the ABN form for voluntary purposes as well (statutorily non-covered services), you may also append the GX modifier to these statutorily non-covered services. So you would code for Medicare, for example: 97140-GXGY. Official description:
GX - NOTICE OF LIABILITY ISSUED, VOLUNTARY UNDER PAYER POLICY
Note that we advise against using the ABN voluntarily for non-covered services. It is better to create your own form to list these services, and equally valid.