A Medicare formulary is a list of drugs covered by Medicare. Each Medicare Prescription insurance plan has a unique formulary. The list of drugs contained in a formulary may change throughout the year.
Some Medicare plans rank prescription drugs on different tiers within their formularies. These tiers are used to rank drugs by cost. Lower-tier drugs require a lower copay than prescription drugs that are ranked in a higher tier.
Doctors may request exceptions in order to qualify patients for lower copayments for prescription drugs that are ranked on a higher tier in the formulary. This is usually done when a doctor believes that a higher-tier prescription drug will be more effective for their patient than a lower-tier drug that treats the same medical condition. Doctors may also request exceptions for drugs that are not listed on a patient's Medicare formulary.
Medicare may change their formulary list throughout the year and has established guidelines for doing so. For patients who are to be affected by these changes, their insurance plan must notify them in writing at least 60 days before the formulary change becomes effective or provide patients who request refills of drugs that have been or are soon to be removed from a Medicare formulary with written notice and a 60-day supply of the drug at covered insurance rates.