Medicare is the federal health insurance program for people 65 and older, regardless of income or health history. Some younger people with disabilities or end-stage renal disease also may have access to. Understanding which parts of Medicare cover what—hospital stays, doctor visits, prescription drugs, preventive care—matters because your choices affect both your coverage and your costs. Many people find the program confusing because it has multiple parts that work differently and require separate decisions.

These articles explain how each part of Medicare works, what you pay for different services, when you can make changes to your coverage, and how Medicare coordinates with other insurance you might have. You'll find information about enrollment periods, late penalties, and how to compare plans so you understand your options before making decisions.