Medicare Basics: What Every New Beneficiary Needs to Know

Who Is Eligible for Medicare?

Medicare is federal health insurance available to:

• People age 65 or older
• People who've received Social Security disability benefits for at least 24 months
• People with End-Stage Renal Disease (ESRD) or ALS (Lou Gehrig's disease), regardless of age

The Four Parts of Medicare, in Plain English

Medicare isn't one plan — it's four separate pieces, and how you combine them determines your coverage and your monthly bill.

• Part A — Hospital care. Part of Original Medicare, run by the federal government.
• Part B — Doctor visits and outpatient care. Also part of Original Medicare.
• Part C (Medicare Advantage) — An all-in-one alternative to Original Medicare, sold by private insurers.
• Part D — Prescription drug coverage, sold by private insurers.

What Does Medicare Part A Cover, and What Does It Cost?

Part A covers inpatient hospital stays, skilled nursing facility care, hospice, and some home health care.

Most people pay nothing for Part A, because they or a spouse paid Medicare taxes for at least 40 quarters (10 years) of work. If that's not the case, you'll pay a monthly premium — in 2026, that's $311/month if you have 30–39 quarters of Medicare-covered work, or $565/month with fewer than 30.

What Does Medicare Part B Cover, and What Does It Cost?

Part B covers doctor visits, outpatient care, durable medical equipment (like wheelchairs and oxygen), home health services, and preventive care such as screenings and vaccines.

The standard Part B premium in 2026 is $202.90/month. If your income is above a certain threshold, you'll pay more through an income-related monthly adjustment (IRMAA), based on your tax return from two years prior — this is one of the details worth reviewing together, since it affects your total cost picture.

What Is Medicare Part C (Medicare Advantage)?

Medicare Advantage plans are sold by private insurers and must cover everything Original Medicare covers — plus many add extra benefits like dental, vision, hearing, prescription drugs, and fitness memberships.

To enroll, you need to already have Parts A and B and live in the plan's service area. Many Advantage plans are available at a $0 monthly premium, and unlike Original Medicare alone, they include an annual out-of-pocket maximum on covered medical costs.

What Is Medicare Part D (Prescription Drug Coverage)?

Part D covers Medicare-approved prescription drugs. You can only enroll if you have Part A and/or Part B. It's either purchased as a standalone plan (to pair with Original Medicare or a Medicare Supplement) or bundled directly into a Medicare Advantage plan.

What Is Medicare Supplement (Medigap) Insurance?

Medigap plans are sold by private insurers to cover the "gaps" Original Medicare leaves behind — coinsurance, copayments, and deductibles. They're standardized and labeled alphabetically (Plans A, B, C, D, F, high-deductible F, G, K, L, M, and N), so the benefits of, say, Plan G are the same no matter which carrier sells it — though the price isn't.

Medigap plans don't use provider networks. You can see any doctor who accepts Medicare, anywhere in the country.

Medigap or Medicare Advantage: Which Should You Choose?

There's no universal right answer — it comes down to how you use healthcare. Medigap generally costs more per month but gives you network-free flexibility and predictable costs. Medicare Advantage typically costs less (often $0) and adds extra benefits, in exchange for using a network and sometimes needing referrals. The right fit depends on your doctors, your prescriptions, and how you travel — which is exactly what a plan comparison should be built around, not a generic recommendation.

When Can You Enroll in Medicare?

Initial Enrollment Period (IEP)

Your Initial Enrollment Period is a 7-month window: the 3 months before the month you turn 65, your birthday month, and the 3 months after. If you're planning to enroll at 65, it's worth contacting Social Security about 3 months ahead of your birthday.

General Enrollment Period (GEP)

The GEP runs January 1 through March 31 every year. It's for people who didn't sign up when first eligible and don't qualify for a Special Enrollment Period. Coverage starts the month after you enroll.

Special Enrollment Period (SEP)

If you have coverage through a current employer (yours or a spouse's), you get an 8-month SEP to sign up for Part A and/or B without penalty, starting the month after employment ends or the group coverage ends — whichever comes first.

Two details trip people up:

• If your employer has fewer than 20 employees, your group plan typically becomes secondary to Medicare — meaning it can require you to pay for services Medicare would have covered, until you're enrolled.
• COBRA doesn't count as active employer coverage for Medicare purposes. Delaying Part B while on COBRA still triggers the late enrollment penalty — sign up for Medicare before your employment or group coverage actually ends.

Still Working at 65? You Have Two Paths

If you're still employed with group health coverage when you turn 65, you generally have two options:

• Enroll during your IEP and drop your employer coverage.
• Defer Medicare while your employer coverage is active, then use your Special Enrollment Period later.

Which makes sense depends on your employer's group plan cost and coverage compared to Medicare's — worth reviewing side by side before you decide either way.

A Simple Countdown If You're Turning 65 Soon

• 6 months out — Learn the basics. If you're still working, get your specific Medicare cost equation analyzed. If you're retiring soon, ask your employer about post-retirement health benefits.
• 3 months out — Start enrolling in Part A and/or B if you're joining a Medicare plan at 65, and start comparing Advantage, Medigap, and Part D options against your actual doctors and prescriptions.
• 1–2 months out — Finalize your plan choice and complete enrollment before your coverage needs to begin.