Medicare is a federal health insurance program in the United States that primarily serves people aged 65 and older, though it also covers certain younger individuals with disabilities or specific health conditions. Established in 1965 under the Social Security Act, Medicare plays a crucial role in ensuring access to healthcare for millions of Americans.

Who Is Eligible for Medicare?

Medicare mainly serves the following groups:

  • People aged 65 or older

  • Individuals under 65 with qualifying disabilities

  • People of any age with End-Stage Renal Disease (ESRD) or Amyotrophic Lateral Sclerosis (ALS)

Eligibility is usually tied to having worked and paid Medicare taxes for at least 10 years (or being the spouse of someone who has).

The Four Parts of Medicare

Medicare is divided into four main parts, each covering different aspects of healthcare:

Part A (Hospital Insurance)

  • Covers inpatient hospital stays, skilled nursing facility care, hospice care, and some home health services.

  • Usually premium-free if you or your spouse paid Medicare taxes for at least 10 years.

Part B (Medical Insurance)

  • Covers outpatient care, doctor visits, preventive services, and medical supplies.

  • Requires a monthly premium, which may vary based on income.

Part C (Medicare Advantage)

  • An alternative to Original Medicare (Parts A and B), offered by private insurance companies.

  • Often includes additional benefits like vision, dental, hearing, and prescription drug coverage.

  • Plans vary by location and provider.

Part D (Prescription Drug Coverage)

  • Helps cover the cost of prescription drugs.

  • Offered through private insurance companies approved by Medicare.

  • Enrollees pay a monthly premium, deductible, and co-pays depending on the plan.

What Medicare Doesn't Cover

While Medicare covers many healthcare services, there are important gaps:

  • Long-term care (e.g., nursing homes)

  • Most dental care

  • Eye exams for glasses

  • Hearing aids

  • Cosmetic procedures

For these and other uncovered expenses, many people buy Medigap policies—private supplemental insurance that helps pay costs like co-pays, co-insurance, and deductibles.

Enrollment and Deadlines

You can first enroll in Medicare during a 7-month Initial Enrollment Period (IEP) that begins three months before your 65th birthday, includes the month you turn 65, and ends three months afterward.

Missing the deadline can result in late enrollment penalties, especially for Part B and Part D, unless you qualify for a Special Enrollment Period (SEP) due to certain life events like losing employer coverage.

Medicare vs. Medicaid

Though similar in name, Medicare and Medicaid are different programs:

  • Medicare is a federal program primarily for seniors and those with disabilities.

  • Medicaid is a state-run program for individuals and families with low incomes and limited resources.

Some people qualify for both programs, known as "dual eligibility."

Why Medicare Matters

Medicare is more than just an insurance program—it's a key pillar of the American healthcare system. It helps millions of older and disabled Americans access necessary medical care without facing devastating financial burdens. With the aging population, Medicare's role is expected to grow even more in the coming decades.