Medicare Part D requires clients to buy plans from a private insurance company. That means that each insurer offering Part D has its own list of covered drugs, the plan formulary.
In order for each insurance company to be able to provide information to potential and existing clients, they break the drugs into various tiers with differing costs. Thus, the drugs in the lowest tier generally have a lower co-insurance or co-payment cost and vice versa — higher-cost drugs usually have a higher co-insurance or co-payment price. There is an exception to this rule, however, if a doctor wants a patient to take a drug in a higher tier, it is possible for patients to obtain the drugs at an affordable price.
The formulary usually stays the same during the year, but it is possible for a plan to change coverage providing it follows Medicare’s rules and regulations. Patients affected by such a change must have at least 60 days’ notice before changes go into effect. Additionally, a refill request must be honored, plus the patient is offered a 60-day supply under the previous plan before changing to the new plan.
Interested in finding out what drugs are covered in your area? Check out Medicare’s plan finder tool at: https://www.medicare.gov/find-a-plan/questions/home.aspx