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Whenever a procedure might not be covered, depending on the diagnosis related to that procedure, Medicare requires an advanced beneficiary notice (ABN) or waiver signed by the patient acknowledging that he or she may have to pay for the procedure if Medicare does not find it medically necessary, says Barbara Cobuzzi, MBA, CPC, CPC-H, an independent coding and reimbursement specialist in Lakewood, N.J.
An electrocardiogram or x-ray, for instance, may be covered, depending on the circumstances outlined in the procedure notes (usually related to the diagnosis).
When physician practices have a signed ABN on file for a particular procedure and date of service (a global ABN for all dates of service and procedures is unacceptable), a -GA modifier (waiver of liability statement on file) on the procedure code tells Medicare that a waiver is on file. With the -GA modifier, Medicare indicates that the doctor may bill the patient if Medicare denies the procedure because it lacked medical necessity.
Medicare pays only for medically necessary services. As a result, some procedures are reimbursed only some of the time. Claims may be rejected because of the ICD-9 code used to justify the procedure or because the service has exceeded Medicares own frequency guidelines.
When a claim has a -GA modifier and Medicare denies the claim, the patients explanation of benefits (EOB) states that the doctor may bill the patient. Without a -GA modifier, Medicare assumes that a valid ABN is not on file, and the EOB on denial from Medicare tells the patient that the doctor may not bill the patient.
Having valid ABNs signed and on file is a target of the Office of Inspector Generals 2000 work plan, and it is considered fraud to provide a service without an ABN and then bill the patient when Medicare denies payment on its medical necessity standards.
For example, a patient comes in with cold arms, and the doctor orders a Doppler. The good news is that no peripheral vascular disease is found; the bad news is that although the doctor felt it was in the best interest of the patient to have the test, Medicare does not consider cold arms as a medically necessary reason for the test. To receive ethical reimbursement, the doctor should have had a valid ABN signed before the test. With a -GA modifier on the claim, the EOB will indicate that the doctor may bill the patient.