Learn the basics
Medicare 101
Medicare can feel like alphabet soup. Here's a plain-language overview of how it's organized and when you can make changes — so you can walk into a conversation already knowing the basics.
The parts of Medicare
Part A — Hospital
Inpatient hospital stays, skilled nursing facility care, hospice, and some home health care. Most people pay no premium for Part A.
Part B — Medical
Doctor visits, outpatient care, preventive services, and medical equipment. Part B has a monthly premium.
Part C — Medicare Advantage
An all-in-one alternative to Original Medicare offered by private insurers. Often bundles Part D and extras like dental, vision, and hearing.
Part D — Prescription Drugs
Helps cover the cost of prescription medications. Offered as a standalone plan or built into many Medicare Advantage plans.
Medicare Supplement (Medigap)
Works alongside Original Medicare to help pay for out-of-pocket costs like copays, coinsurance, and deductibles.
When can you enroll?
Initial Enrollment Period
The 7-month window around your 65th birthday — starts 3 months before the month you turn 65 and ends 3 months after.
Annual Election Period (AEP)
October 15 – December 7 each year. Switch, join, or drop Medicare Advantage and Part D plans; changes take effect January 1.
Medicare Advantage Open Enrollment
January 1 – March 31. If you’re already in a Medicare Advantage plan, you can switch once or return to Original Medicare.
Special Enrollment Periods
Life events — moving, losing other coverage, and more — can open a window to make changes outside the usual dates.
Still have questions?
A licensed agent can walk you through your options at no cost. We're happy to help in English or Spanish.
For official, complete information on all your options, visit Medicare.gov or call 1-800-MEDICARE.