Review of Medicare Payments for Laboratory Tests Billed With an AY Modifier by DVA Laboratory Services, Inc. 

DVA Laboratory Services, Inc. (DVA), did not always comply with Medicare requirements for tests billed with an AY modifier for beneficiaries with end-stage renal disease (ESRD). Specifically, for 62 of the 100 beneficiary-days, DVA submitted separate claims using the AY modifier for tests furnished for the treatment of ESRD contrary to the consolidated billing requirement. In addition, DVA did not always comply with other Medicare requirements. These errors occurred primarily because DVA did not have adequate controls to comply with certain Medicare requirements. On the basis of our sample results, we estimated that Medicare overpaid DVA at least $989,000 for tests that were furnished for the treatment of ESRD.