Medicare Basics

Medicare Made Simple.

Medicare has Parts A through D, two main coverage paths, and several enrollment windows — and it all clicks into place faster than you'd think. This guide walks you through everything, in plain English.

The Four Parts Two Coverage Paths Medigap Eligibility Enrollment What's Right for Me?
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A Part A Hospital Insurance B Part B Medical Insurance C Part C Medicare Advantage D Part D Prescription Drugs Medigap Fills the gaps
The One-Minute Overview

What exactly is Medicare?

Medicare is the federal health insurance program primarily for people 65 and older — and for some younger people with qualifying disabilities. It's funded by the U.S. government but delivered through a mix of federal programs and private insurers.

67M+ Americans currently enrolled
10,000 Turn 65 every single day
Free to work with a licensed agent
PARTS A · B · C · D

The Four Parts of Medicare

Think of Medicare as a set of building blocks. Each part covers a different piece of your healthcare — and they're designed to work together.

A

Hospital Insurance Part A

Covers inpatient & facility care

  • Inpatient hospital stays
  • Skilled nursing facility care
  • Hospice care
  • Some home health services
Free for most people (40+ work quarters). Deductible ~$1,632/stay in 2024.
B

Medical Insurance Part B

Covers doctors & outpatient care

  • Doctor & specialist visits
  • Outpatient procedures
  • Preventive screenings & vaccines
  • Durable medical equipment
Standard premium ~$185/month in 2025. After deductible, you pay 20% with no cap.
C

Medicare Advantage Part C

Private all-in-one alternative to A + B

  • Everything Parts A & B cover
  • Usually includes Part D drug coverage
  • Dental, vision & hearing (most plans)
  • Annual out-of-pocket maximum
Often $0 added premium. You still pay Part B. Network-based care.
D

Prescription Drugs Part D

Covers brand-name & generic medications

  • Generic and brand-name drugs
  • Preferred pharmacy discounts
  • Mail-order options
  • Some vaccines
$10–$50+/month for standalone plans. Skip it and you may face a lifetime penalty.
The key connection

Parts A and B form the foundation — everyone on Medicare starts here. Parts C and D are then added on top, either as a combined Advantage plan (C) or as separate coverage you choose alongside Original Medicare.

The Big Decision

Two Paths to Medicare Coverage

Once you have Parts A and B, you choose one of two main routes for the rest of your coverage. This is the most important decision most Medicare beneficiaries make.

A B Medigap D

Path A — Original Medicare

The federal government manages your coverage directly. You add a Medigap plan to cap your costs, plus a standalone Part D plan for drugs.

  • See any doctor or specialist who accepts Medicare — no network
  • No referrals needed for specialists
  • Nationwide coverage, including travel across the U.S.
  • Medigap caps your out-of-pocket costs at a predictable level
  • No bundled dental, vision, or hearing
  • Higher monthly premiums when Medigap is added
Best For

People who see multiple specialists, travel frequently, or want total predictability in annual costs.

Part C Includes A + B + usually D

Path B — Medicare Advantage

A private insurer bundles Parts A, B, and usually D into one plan — often adding dental, vision, and hearing Medicare doesn't cover.

  • Often $0 additional monthly premium
  • Annual out-of-pocket maximum protects you
  • Dental, vision & hearing usually included
  • Drug coverage typically bundled in
  • Network-based — must use plan's doctors
  • Plans vary by county; less consistent if you move
Best For

People who want lower monthly costs, don't mind a provider network, and want extras like dental and vision bundled in.

You can only be on one path at a time.

You cannot have both Medicare Advantage and a Medigap plan simultaneously. If you choose Advantage, you cannot use a Medigap policy.

Medicare Supplement

Medigap: Filling What Original Medicare Leaves Behind

Original Medicare covers most costs — but it leaves gaps. You typically owe 20% of every outpatient service with no annual cap. Medigap (Medicare Supplement) plans are sold by private insurers to cover those remaining costs.

  • Part A hospital deductible and coinsurance
  • Part B coinsurance — the 20% you'd otherwise owe
  • Skilled nursing facility coinsurance
  • Foreign travel emergency care (select plans)
  • Predictable, fixed monthly costs year-round

Standardized by federal law. Each plan letter (A through N) has the same benefits regardless of which insurer sells it. The difference between insurers is price, not coverage — so comparing premiums is worthwhile.

Medigap Plan Letters
  • A
  • B
  • C
  • D
  • F
  • G
  • K
  • L
  • M
  • N
Most popular plans (G, N, F) Also available
Plan G Popular

The most comprehensive plan available to new enrollees. Covers nearly everything except the Part B deductible (~$240/year).

Plan N Popular

Lower premiums than Plan G, but you pay small copays for some office visits and ER visits. Good balance of cost and coverage.

Plan F Popular

Most comprehensive plan available — but only for those who turned 65 before Jan 1, 2020. Covers the Part B deductible too.

Medigap requires you to also carry a separate Part D plan for prescription coverage. It cannot be paired with Medicare Advantage.

Who Qualifies

Are You Eligible for Medicare?

Most people qualify at 65, but eligibility can begin earlier for some. Here's a quick look at who qualifies and what affects your costs.

Turning 65

U.S. citizens and permanent residents who are 65 or older are eligible for Medicare. You also need to be eligible for Social Security or Railroad Retirement benefits — or have a spouse who is.

  • U.S. citizen or lawful permanent resident
  • Lived in the U.S. for at least 5 years
  • 65 or older

Disability (Under 65)

If you've received Social Security Disability Insurance (SSDI) for 24 months, you automatically become eligible for Medicare before 65. Certain conditions qualify immediately.

  • 24 months of SSDI benefits
  • ALS (Lou Gehrig's Disease) — immediate
  • End-Stage Renal Disease (ESRD) — immediate

Work History & Costs

Your work history affects whether Part A is free. Part B has a standard premium for everyone, though higher earners pay more through IRMAA income-related adjustments.

  • 40+ quarters: Part A is free
  • 30–39 quarters: ~$278/month for Part A
  • Under 30 quarters: ~$505/month for Part A
Still working and covered by employer insurance at 65?

You may be able to delay Part B without penalty, as long as your employer group plan is considered "creditable coverage." When that coverage ends, you'll have a Special Enrollment Period. Ask your HR department and a Medicare agent before deciding.

Timing Matters

Enrollment Periods — Know Your Windows

Enrolling at the wrong time — or missing a window — can mean gaps in coverage or lifetime late-enrollment penalties. Here are the four key periods to know.

IEP

Initial Enrollment Period

7 months around your 65th birthday

Starts 3 months before your birthday month, includes the month you turn 65, and runs 3 months after. This is your primary window — don't miss it.

AEP

Annual Enrollment Period

Oct 15 – Dec 7 every year

Switch between Original Medicare and Medicare Advantage, change your Part D plan, or change Advantage plans. Changes take effect January 1.

MA OEP

Medicare Advantage Open Enrollment

Jan 1 – Mar 31 every year

Already on Medicare Advantage? You can make one switch — to a different Advantage plan or back to Original Medicare — during this window.

SEP

Special Enrollment Period

Triggered by qualifying life events

Lost employer coverage, moved out of your plan's area, or other qualifying events give you a Special Enrollment Period — typically 60 days from the event.

Late Enrollment Penalties Are Permanent

If you don't enroll in Part B when first eligible and you don't have other qualifying coverage, your Part B premium increases 10% for every 12-month period you were eligible but didn't sign up — and that penalty lasts for life. The same applies to Part D drug coverage. The best defense is enrolling on time or working with an agent who understands exactly when your window opens.

Find Your Fit

What Might Be Right for You?

Your health, budget, and lifestyle all shape the right Medicare choice. Here are four common situations — click any to explore.

Your drug list matters more than the premium. Compare each plan's formulary and pharmacy network against the exact medications you take — a plan that looks cheap can cost far more at the counter.

Original Medicare with a Medigap plan lets you see any specialist who accepts Medicare, with no referrals and no network. If you prefer Advantage, check that every one of your doctors is in the plan's network first.

Original Medicare travels with you anywhere in the U.S., and select Medigap plans add foreign travel emergency cover. Advantage plans are county-based, so care away from home is usually limited to emergencies.

Medicare Advantage often costs $0 extra each month on top of your Part B premium. The trade-off is copays as you use care, so weigh the monthly saving against the plan's annual out-of-pocket maximum.

Still not sure? That's completely normal.

A licensed agent can review your doctors, prescriptions, and budget and recommend exactly which plan fits your situation — at no cost to you.

Talk to a Local Agent
Free · Local · No Pressure

Ready to Talk to Someone Who Knows Medicare Inside and Out?

Reading a guide is a great first step — but Medicare decisions have real financial consequences. A licensed local agent knows exactly which plans are available in your county, which ones cover your doctors and medications, and what everything will actually cost you.

Best of all: it costs you absolutely nothing. Agents are paid by insurance carriers, not by you. There's no pressure, no obligation, and no rush to enroll in anything.

Find a Licensed Agent Near Me
Licensed & independently verified

Every agent holds an active state license and completes annual AHIP certification.

Local market expertise

Your agent knows which plans, networks, and providers are actually available in your county.

Always free for consumers

Agents are compensated by carriers — you never pay a cent for their guidance.

Annual plan reviews included

A good agent checks in each open enrollment period to make sure you're still on the right plan.