Final answer:
An ABN form needs to be signed by patients who have Medicare insurance before any service or procedure is performed.
Step-by-step explanation:
The correct answer is option 3) Medicare; before any service or procedure is performed.
An ABN form, or Advanced Beneficiary Notice, needs to be signed by patients who have Medicare insurance before any service or procedure is performed. The ABN form informs the patient that Medicare might not cover the service or procedure, and the patient will be responsible for the costs if Medicare denies payment.
This form is important because it allows the patient to make an informed decision about whether to proceed with the service or procedure knowing that they may have to pay for it out of pocket if Medicare does not cover it.