The Zostavax vaccine is covered by Medicare Part D, which is the prescription drug coverage program. However, it is important to note that not all Medicare Part D plans cover the Zostavax vaccine. It is recommended to check with your specific Medicare Part D plan to confirm coverage. Additionally, there may be a cost-sharing requirement, such as a copayment or coinsurance, depending on your plan. It is always a good idea to consult with your healthcare provider or Medicare representative to get the most accurate and up-to-date information on your specific coverage.