Final answer:
Medicare Part B does not require an AOB form for processing in urgent or emergent care situations, as obtaining the form may be impossible. Providers will be reimbursed, but payments go directly to the patient.
Step-by-step explanation:
The only occasion when Medicare Part B can be processed without an Assignment of Benefits (AOB) form being signed is when the services are rendered in a situation that involves urgent or emergent care. In such circumstances, obtaining an AOB form may not be feasible due to the patient's medical condition or incapacity. The healthcare provider can still submit a claim to Medicare and receive reimbursement, but the payment will be sent directly to the patient, who is then responsible for paying the provider.