En español | Your Part D drug plan cannot place a limit on the number of prescriptions you fill, either in a year or in a lifetime. However, Part D plans don’t cover all drugs, and your plan won’t pay for any drug that it doesn’t cover — unless you and your doctor apply for an “exception” based on your medical needs and the plan agrees to cover the drug in your case.
Part D plans can impose “quantity limit” restrictions on some drugs. This doesn’t mean that the plan will cover your meds for a certain length of time then stop. Rather, it means that your doctor has prescribed a dosage or quantity that’s higher than the plan considers normal to treat your medical condition. So the plan won’t cover the drug unless your doctor writes a new prescription for a lesser amount or convinces your plan that the higher amount is necessary to treat you effectively. The plans, not Medicare, decide which drugs should have quantity limit restrictions.
Also, Medicare law excludes some types of medications from Part D coverage:
Sometimes Medicare will allow coverage for drugs in these categories if they are used for a “medically acceptable” purpose — for example, cough medicines prescribed to alleviate serious conditions like asthma; or drugs for impotency when prescribed to treat different medical conditions that affect veins and arteries; or antismoking drugs if prescribed by a doctor rather than bought over the counter.