Individuals choosing a Medicare Part D policy should read the plan formulary to find out if the drugs that they use are on the list, reports WebMD. They should also check that the quantities and dosages they need are available. If the drugs they need are not part of the policy formulary, they should ask their doctors if they can substitute other listed drugs for the ones they have been using.
In their formularies, insurance companies relegate drugs into three or four different tiers, explains Drugs.com. Drugs in lower tiers are less expensive generic drugs, while those in higher tiers are more expensive brand-name drugs. Medicare Part D plan formularies are not always consistent, and drugs in lower tiers in one policy may be in higher tiers in other policies. Additionally, some plans charge deductibles before insurance companies pay for covered drugs, while other plans do not.
Sometimes Medicare recipients qualify for exceptions that allow them to purchase drugs at lower copayments even when the drugs are in higher tiers, according to Medicare.gov. Although Medicare allows insurance companies to make changes in their plan formularies, the companies must give beneficiaries advance notice and provide a supply of the original drug for a limited time. Once Medicare recipients enroll in a plan, they are unable to switch to another plan until the open enrollment period the following year, cautions Drugs.com.