What Is Medicare?
Medicare is a federal health insurance program in the United States, primarily designed for people aged 65 and older. It also covers certain younger individuals with qualifying disabilities and people with End-Stage Renal Disease (ESRD) or ALS (Lou Gehrig's disease). Administered by the Centers for Medicare & Medicaid Services (CMS), Medicare is one of the largest health insurance programs in the country.
Understanding Medicare starts with its four distinct parts, each covering a different aspect of your healthcare needs.
Medicare Part A: Hospital Insurance
Part A is often referred to as hospital insurance. It helps cover:
- Inpatient hospital stays
- Skilled nursing facility care (under certain conditions)
- Hospice care
- Some home health services
Most people do not pay a monthly premium for Part A if they or their spouse paid Medicare taxes for at least 10 years (40 quarters) while working. However, there are deductibles and coinsurance costs when you use services.
Medicare Part B: Medical Insurance
Part B covers outpatient medical services, including:
- Doctor visits and preventive care
- Outpatient surgeries and procedures
- Lab tests, X-rays, and diagnostic imaging
- Mental health services
- Durable medical equipment (wheelchairs, walkers, etc.)
Part B requires a monthly premium, which is income-adjusted. Most enrollees pay the standard premium set annually by CMS. There is also an annual deductible, after which Medicare typically pays 80% of approved costs and you pay the remaining 20%.
Medicare Part C: Medicare Advantage
Medicare Advantage, or Part C, is an alternative way to receive your Medicare benefits. Instead of getting coverage directly through the federal government, you enroll in a private insurance plan that has been approved by Medicare. These plans must cover everything that Original Medicare (Parts A and B) covers, and most also include:
- Prescription drug coverage (Part D)
- Dental, vision, and hearing benefits
- Fitness programs and wellness perks
Medicare Advantage plans vary significantly in cost, network, and coverage, so comparison shopping is essential.
Medicare Part D: Prescription Drug Coverage
Part D adds prescription drug coverage to Original Medicare. It is offered through private insurers approved by Medicare and is an optional but highly recommended addition for most enrollees. Key features include:
- Coverage for a wide range of brand-name and generic drugs
- A formulary (list of covered drugs) that varies by plan
- Monthly premiums, deductibles, and copays that differ by plan
Without Part D, you may face a late enrollment penalty if you sign up later and did not have other creditable drug coverage.
How the Parts Work Together
| Part | Type | What It Covers | Who Provides It |
|---|---|---|---|
| Part A | Hospital Insurance | Inpatient, hospice, skilled nursing | Federal government |
| Part B | Medical Insurance | Outpatient, doctor visits, preventive care | Federal government |
| Part C | Medicare Advantage | Combines A & B, often adds D + extras | Private insurers |
| Part D | Drug Coverage | Prescription medications | Private insurers |
Original Medicare vs. Medicare Advantage
You generally have two main paths to receiving your Medicare benefits:
- Original Medicare (Parts A + B) with an optional Part D drug plan and/or a Medigap supplemental policy.
- Medicare Advantage (Part C), which bundles your coverage through a private plan and usually includes drug coverage.
Both approaches have trade-offs in terms of cost, flexibility, and coverage. The right choice depends on your health needs, preferred doctors, medications, and budget.
Next Steps
Understanding the basics is the foundation for every Medicare decision you'll make — from when to enroll to which plan type suits your lifestyle. Explore the other articles on this site to dive deeper into enrollment periods, costs, and how to compare plans.