Medicare Basics: Parts A, B, C, D and What to Sign Up For

What Medicare is

Medicare is the federal health insurance program for:

• People age 65 or older
• People under 65 with certain disabilities (after 24 months of Social Security Disability)
• People of any age with End-Stage Renal Disease (ESRD) or ALS

Roughly 65 million Americans are enrolled in Medicare. Unlike Medicaid (which is income-based), Medicare is age- or disability-based. Your income doesn't determine eligibility.

Need help understanding your options? Call 1-800-MEDICARE (1-800-633-4227) — staffed 24/7 with help in English and Spanish, or call your state's free SHIP counselor (Senior Health Insurance Assistance Program) at shiphelp.org.

The four parts

Part A — Hospital Insurance

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

Cost: Free for most people (if you or your spouse paid Medicare taxes for 10+ years working). Otherwise up to $505/month in 2026.

Part B — Medical Insurance

Covers doctor visits, outpatient care, preventive services, durable medical equipment, and some home health.

Cost: Standard premium is $185/month in 2026 (higher for high earners). Most people pay this premium directly from their Social Security check.

Part C — Medicare Advantage

A bundled plan from a private insurer that combines Part A + Part B (and usually Part D + extras like dental and vision). About half of Medicare beneficiaries now choose Advantage plans.

Cost: Variable. Often $0/month additional premium (you still pay Part B), but plans have copays and network restrictions.

Part D — Prescription Drugs

Covers prescription medication. Required if you don't have other "creditable" drug coverage — otherwise you pay a permanent late enrollment penalty.

Cost: Average $35/month in 2026, plus copays. The 2025 Inflation Reduction Act capped out-of-pocket Part D drug costs at $2,000/year — a major change for people on expensive medications.

When to enroll

Initial Enrollment Period (IEP)

The 7-month window around your 65th birthday: 3 months before, the month of, and 3 months after. Sign up during this window to avoid late penalties.

Special Enrollment Period (SEP)

If you're working past 65 and have job-based coverage, you can delay Medicare without penalty. When you (or your spouse) leave that job, you have an 8-month SEP to enroll.

General Enrollment Period (GEP)

January 1 – March 31 each year. For people who missed their IEP and don't have an SEP. Coverage starts the month after you sign up. Late enrollment penalties apply.

Open Enrollment for Medicare Advantage / Part D

October 15 – December 7 each year. Time to switch plans, add Part D, or move between Original Medicare and Advantage.

Original Medicare vs. Medicare Advantage

| | Original Medicare (Parts A + B + D) | Medicare Advantage (Part C) | |---|---|---| | Doctor choice | Any doctor accepting Medicare | Plan's network only | | Referrals | Not required | Often required | | Out-of-pocket cap | None (unless you add Medigap) | Yes ($8,300 cap in 2026) | | Extras | Not included | Often dental, vision, hearing, gym | | Travel coverage | Nationwide | Limited outside service area |

Most experts recommend: Original Medicare + a Medigap plan + a Part D drug plan if you can afford it (best protection). Medicare Advantage if monthly cost matters more (lower premiums, more restrictions).

Help paying for Medicare

If your income is limited, several programs help:

• Medicare Savings Programs (MSP) — Pay your Part B premium ($185/mo in 2026). Apply through your state Medicaid office.
• Extra Help / Low-Income Subsidy (LIS) — Reduces or eliminates Part D drug costs. Apply through Social Security.
• PACE (Programs of All-Inclusive Care for the Elderly) — Wraps Medicare and Medicaid into one program for frail seniors who want to stay home.

How to enroll

1. If you're already getting Social Security, you'll be enrolled in Parts A and B automatically the month you turn 65.
2. If you're not yet on Social Security, sign up at ssa.gov/medicare or call 1-800-772-1213.
3. Add Part D by enrolling in a plan at medicare.gov.
4. Consider Medigap (Original Medicare path) — buy from a private insurer in your state.

A note from us

Medicare decisions are made under time pressure (the IEP is only 7 months) and the choices stick — switching from Medicare Advantage back to Original Medicare can be hard later. A team members can connect you with your state's free SHIP counselor for unbiased, personalized advice. Call (844) 572-3682 and we'll get you to the right person.