Offered by private insurance companies, Medicare Part D prescription drug plans help you pay for your prescription drugs.

• You must have Parts A (Hospital) or B (Medical) (Original Medicare) to join a Part D prescription drug plan.
• Part D coverage is often purchased as a stand-alone Part D prescription drug plan.
• You can also receive Part D benefits from a Medicare Advantage plan that includes prescription drug coverage.
• With a stand-alone Part D prescription drug plan, you pay a separate monthly premium to an insurance company.
• Medicare Advantage plans with prescription drug coverage generally don't require you to pay an extra Part D premium.
• Prescription drug coverage and costs vary from plan to plan.
• Each plan has a formulary — a list of the specific drugs the plan covers.
• Many plan formularies also have tiers that place covered drugs into different costs levels.
• Drugs in a lower tier will generally cost you less than drugs in a higher tier.