When and how to use ABNs.
D014487:Centers for Medicare and Medicaid Services, U.S.; D005568:Forms and Records Control; D019458:Insurance Coverage; D006278:Medicare / Q000191:economics*; D010358:Patient Participation; D011216:Practice Management, Medical / Q000458:organization & administration*; D012051:Reimbursement Mechanisms / Q000458:organization & administration*; D014481:United States