Medicare 101
Your complete, plain-English Medicare guide
New to Medicare? Start here. Medicare has four parts — A, B, C, and D. Below are the basics, then dig into any topic.
Part A — Hospital
Inpatient hospital, skilled nursing, hospice. Usually premium-free if you worked 10+ years.
Part B — Medical
Doctor visits, outpatient care, preventive services. Monthly premium set by income.
Part C — Advantage
A private all-in-one alternative bundling A, B, and usually D, often with extras.
Part D — Drugs
Prescription drug coverage, with a 2026 out-of-pocket cap of $2,100.
2026 IRMAA — income-related Part B & Part D surcharges
Higher-income beneficiaries pay a monthly surcharge on top of the standard Part B premium. IRMAA is based on your 2024 MAGI (the tax return filed in 2025) — not your current income. About 8% of Medicare enrollees pay IRMAA.
| 2024 MAGI — Single filer | 2024 MAGI — Married filing jointly | Part B monthly premium | Part D surcharge / mo |
|---|---|---|---|
| ≤ $109,000 | ≤ $218,000 | $202.90 Standard | $0.00 |
| $109,001 – $137,000 | $218,001 – $274,000 | $284.10 | $14.50 |
| $137,001 – $171,000 | $274,001 – $342,000 | $405.80 | $37.50 |
| $171,001 – $205,000 | $342,001 – $410,000 | $527.50 | $60.40 |
| $205,001 – $499,999 | $410,001 – $749,999 | $649.20 | $83.30 |
| ≥ $500,000 | ≥ $750,000 | $689.90 | $91.00 |
Source: SSA POMS HI 01101.020 · 2026 figures · Married filing separately uses different thresholds. Part D surcharge is added on top of your plan's own premium. Use our free IRMAA calculator →
All Medicare 101 articles
What Is Medicare?
Medicare is federal health insurance for people 65+ and some younger people with disabilities. Here's how the four parts fit together.
Medicare vs Medicaid
Medicare is age-based federal insurance; Medicaid is income-based. Some people qualify for both. Here's how they differ.
Medicare Eligibility
Most people qualify for Medicare at 65. Some younger people with disabilities qualify earlier. Here's how to know.
Medicare Enrollment Periods
IEP, AEP, and SEPs — the windows to enroll in or change Medicare, and how to avoid penalties.
How to Enroll in Medicare
A simple step-by-step for enrolling in Medicare at 65 — and how a local agent makes it painless.
Understanding Medicare Part D
How Part D drug coverage works, the 2026 $2,100 cap, formularies, and the late-enrollment penalty.
Medicare for Veterans
How VA benefits and Medicare work together, and why many veterans still enroll in Part B.
Medicare Costs Breakdown
Premiums, deductibles, and out-of-pocket numbers that matter for 2026 — in plain English.
Getting-started questions
Is Medicare free?
Part A is usually premium-free if you or your spouse paid Medicare taxes 10+ years. Part B has a monthly premium. Advantage and Part D plans vary — some are $0 premium.
Is Medicare the same as Medicaid?
No. Medicare is federal health insurance based mainly on age. Medicaid is a state/federal program based on income. Some people qualify for both (dual-eligible).
When is Medicare's Annual Enrollment Period?
October 15 to December 7 each year. Changes you make take effect January 1. We review your plan every fall to make sure it's still your best fit.