What is a formulary in relation to Medicare Part D?

A formulary in relation to Medicare Part D is indeed a list of covered drugs provided by a Part D plan. This list outlines the specific medications that are covered under a Medicare Part D prescription drug plan, which is critical for beneficiaries as it helps them know what medications they can access without incurring high out-of-pocket costs. Each Medicare Part D plan has its own formulary, and the list can vary significantly from one plan to another, meaning that beneficiaries should carefully evaluate their options based on the medications they need. The formulary typically includes information about coverage tiers, which indicate different cost-sharing levels for various drugs, as well as any prior authorization or step therapy requirements that may apply.

The other options do not accurately describe a formulary in this context. For instance, a list of healthcare providers pertains more to provider networks rather than medication coverage, while a list of excluded services and a list of preventive services do not relate specifically to the coverage of prescription drugs under Medicare Part D.