Understanding Medicare starts with recognizing it as a federal health insurance program in the United States, primarily for individuals aged 65 and older, as well as younger people with certain disabilities or end-stage renal disease. To grasp its structure, break it down into key parts: Original Medicare includes Part A (hospital insurance covering inpatient stays, skilled nursing, hospice, and home health) and Part B (medical insurance for outpatient care, doctor visits, preventive services, and durable medical equipment), while Part D adds prescription drug coverage through private plans. For enhanced benefits, consider Medicare Advantage (Part C), which bundles A, B, and often D with extras like dental or vision from private insurers, or Medicare Supplement Insurance (Medigap) to fill gaps in Original Medicare costs like deductibles and coinsurance. Enrollment typically begins during your Initial Enrollment Period around your 65th birthday, with Annual Enrollment Periods for changes; factors like premiums, out-of-pocket limits, and provider networks are crucial to evaluate. Consulting resources like Medicare.gov or a licensed advisor can simplify navigating eligibility, costs, and options for personalized coverage as of 2026 updates.