On the ABN form, blanks A-C make up the _____.

Blanks A-C on the Advance Beneficiary Notice (ABN) form are essential for identifying and providing context regarding the patient and the services they are receiving. Specifically, these sections typically include the patient's name, Medicare number, and the date of the notice. This introductory information is crucial because it helps ensure that the healthcare provider and the patient have clarity on who the notice pertains to and the particular services being discussed.

In this context, the “Header” serves as a key reference frame, ensuring that everyone involved understands the particulars of the notice before considering the details provided in the body of the form. Therefore, blanks A-C effectively create the foundation of the ABN, aligning with the essential function of a header in a document which is to provide primary identifying information and context before the reader delves into the details.