Once you have Medicare Part A (hospital) and Part B (outpatient), you have choices to select from. Whatever your choice, Medicare wants you to include drug coverage in your selection.
Some people want the same freedom they had with a PPO, therefore, they may want to consider a Medicare supplement (also known as a Medigap policy). These supplements are defined by Medicare and offered by insurance companies. The word PLAN comes before the letter of the alphabet which defines the benefits of that plan as defined by Medicare. These plans have a monthly premium. If you select a Medicare supplement, then you will also need to select a stand-alone drug plan to cover your Part D (drug benefit). The drug plans offered for each regional area will have different premiums, may or may not have a deductible, and vary regarding what prescription drugs they cover at what tier (which affects the cost of the drug).
Other people may have been on an HMO or may financially not want to pay the monthly premium for a supplement and a stand-alone drug plan. They may be interested in the Medicare Advantage plans (MAPDs — this is Part C) which cover not only medical care but also include a drug benefit. Each medical group has a select group of MAPDs that they take, so the beneficiary should only focus on those plans that their medical group takes.