What is a requirement for consumers enrolling in Medicare Prescription Drug Plans?

The requirement that consumers must reside in the plan's service area is essential for enrolling in a Medicare Prescription Drug Plan. Each plan operates within specific geographical boundaries, which helps ensure that the plan can effectively manage and provide services to its members. This requirement helps ensure that enrollees have access to local pharmacies and services that the plan covers.

In contrast, the other options do not accurately reflect the rules governing Medicare Prescription Drug Plans. Not all drugs are universally covered by all plans; each plan has its formulary— a list of covered drugs. The benefits can vary significantly between different plans, with each offering unique coverage levels, costs, and drug lists. Furthermore, Medicare Part D is distinct and is not automatically included in Medicare Supplement Insurance Plans, which are designed primarily to cover gaps in original Medicare rather than providing drug coverage directly.