No. There is no limit on the amount of drugs that can be covered. However, each Medicare drug plan will have a list of the specific prescription drugs that it will cover (called a formulary), and not all plans will cover exactly the same drugs. If your doctor thinks you need a drug that is not on the plan’s list, you can ask the plan for an “exception” to its list. Plans may cover both generic and brand-name prescription drugs. These drugs must be approved by the FDA (Food and Drug Administration) as safe and effective.
(Source: U.S. Department of Health & Human Services)