The coverage gap associated with expanded cost-sharing applies to which part of Medicare?

The coverage gap associated with expanded cost-sharing specifically pertains to Medicare Part D, which is the prescription drug coverage component of Medicare. Under Part D, beneficiaries may experience a coverage gap, commonly referred to as the "donut hole." After reaching a certain spending threshold on their medications in a given year, beneficiaries enter this gap, where they are responsible for a higher percentage of their drug costs until they reach the catastrophic coverage threshold.

This concept is unique to Part D, as the other parts of Medicare—Part A (hospital insurance), Part B (medical insurance), and Part C (Medicare Advantage plans)—do not have this same type of coverage gap. For instance, while Part A and Part B may have deductibles and coinsurance, they do not create a situation where beneficiaries are financially liable for a portion of their care after reaching a certain spending limit in the way that Part D does. Similarly, Part C plans may have their own cost-sharing structures but are generally built upon the original Medicare framework, which does not include a coverage gap like that of Part D.