Pathology/Lab Coding Alert

Question: We recently had flow cytometry charges denied by Medicare for "diagnosis not medically necessary." I can now see from our carrier's LCD that the diagnosis is not listed as covered. In the future, should I not bill these cases, since I know they're not covered?

Arkansas Subscriber

Answer: For flow cytometry (88187-88189, Flow cytometry, interpretation ...) or any other test with a Local Coverage Determination (LCD) or National Coverage Determination (NCD), you can know in advance if the service is covered for a given diagnosis. In the event that you have a non-covered diagnosis, you can still bill for the test, but you need to use modifiers to explain the situation.

If you're performing a service that you don't expect Medicare to cover because it's not medically necessary, you should get the patient to sign an Advance Beneficiary Notice of Noncoverage (ABN). The notice indicates that the beneficiary realizes that Medicare might not cover the service, but that she wants the service anyway and she agrees to be financially responsible.

If you get the signed ABN, you should code the procedure and append modifier GA (Waiver of liability statement issued as required by payer policy, individual case). If you have the ABN on file and use the modifier, you should be able to bill the patient when you get the Medicare explanation of benefits (EOB) stating that the procedure is denied.

If you fail to get a signed ABN, then you can still file the claim with Medicare, but you should append a different modifier to the procedure code: GZ (Item or service expected to be denied as not reasonable and necessary). Unfortunately, you cannot bill the patient upon denial if you don't have the signed ABN. But using the modifier keeps you out of possible accusations of fraud.

Because pathologists and labs don't "see" the patient, you might have to engage the help of your physician clients to get the signed ABN. For example, you could establish a policy with your clients, giving them the list of payable diagnoses for flow cytometry and asking them to get a signed ABN from the patient if they're requesting the procedure for a different purpose.