Make sense of Medicare, then choose with confidence.

As of March 2026, KFF reports 55% of eligible Medicare beneficiaries, roughly 35.2 million of 64.2 million people, are enrolled in a Medicare Advantage plan, up from 19% in 2007.

What Medicare actually costs in 2026

Numbers first, because most Medicare pages avoid them. Part B costs $202.90 per month in 2026, up $17.90 from 2025, with a $283 annual deductible. Part A is premium-free for approximately 99% of beneficiaries, because they have at least 40 quarters, about 10 years, of Medicare-covered work. If you do not qualify, Part A runs $311 per month at 30 to 39 quarters or $565 with fewer than 30. The Part A hospital deductible is $1,736 per benefit period, which covers your first 60 inpatient days, then $434 per day for days 61 to 90.

Higher earners pay a surcharge called IRMAA, which begins above $109,000 of income for a single filer and $218,000 filing jointly, measured from your tax return two years earlier. CMS says it affects roughly 8% of Part B enrollees. All figures here come from the CMS 2026 Parts A and B premiums fact sheet.

The Part D change worth knowing about

For 2026 there is a hard $2,100 cap on what you pay out of pocket for covered Part D drugs. Reach it and you pay nothing more for covered drugs that year. The cap came from the Inflation Reduction Act and first took effect in 2025 at $2,000, replacing the old coverage gap, and for anyone on expensive maintenance medication it is the single biggest improvement to Medicare in years. The maximum Part D deductible in 2026 is $615. Plan premiums themselves vary by plan, so we will not quote an average that would not apply to you.

Advantage or Supplement, honestly

This is the real fork, and neither answer is universally right.

Medicare Advantage replaces how you receive Parts A and B through a private plan, usually with a lower premium, a network, and extras like dental or vision. Original Medicare with a Medigap Supplement costs more monthly but lets you use any provider who accepts Medicare and makes your out-of-pocket costs far more predictable.

The honest tradeoff: Advantage tends to suit people who are healthy, stay local, and want a low premium. A Supplement tends to suit people who travel, want specific specialists, or expect significant care and would rather pay a known premium than variable cost sharing. What decides it in practice is your doctor list and your drug list, which is why we run both before recommending either.

The windows, and the one that does not come back

Your Initial Enrollment Period is 7 months: the 3 months before your 65th birthday month, that month, and the 3 months after. Medicare Open Enrollment, the annual window for changing Medicare Advantage and Part D plans, runs October 15 to December 7 each year for coverage starting January 1. The General Enrollment Period, for people who missed initial Part A and Part B enrollment, runs January 1 to March 31, and people already in an Advantage plan get a separate January 1 to March 31 window to change it.

Then there is the one people miss. Your Medigap Open Enrollment Period is a single 6-month window that opens the first month you have Part B and are 65 or older. Inside it, insurers cannot medically underwrite you, turn you down, or charge more for pre-existing conditions. It does not repeat. Miss it and in most states your health history can determine whether you can buy a Supplement at all. If you take one thing from this page, take that.

What late enrollment costs

Both penalties are permanent, which is what makes them worth avoiding. Part B adds 10% of the standard premium for every full 12-month period you could have enrolled and did not, charged for as long as you have Part B. Medicare.gov's own 2026 example: 24 months late is a 20% penalty, taking $202.90 to about $243.50 a month, every month, for life.

Part D adds 1% of the national base premium, $38.99 in 2026, for each month you went without creditable drug coverage, triggered once a gap reaches 63 days. It follows you even if you change plans, and it recalculates annually as the base premium moves. This is why enrolling in a cheap drug plan you barely use is often the right call.

Medigap plan letters

There are 10 standardized plan letters in most states: A, B, C, D, F, G, K, L, M, and N. Because they are standardized, Plan G from one carrier covers the same things as Plan G from another, so price and service are the differences that matter. Massachusetts, Minnesota, and Wisconsin standardize their plans differently.

One rule catches people: Plans C and F are not available to anyone newly eligible for Medicare on or after January 1, 2020. That covers people who turned 65 on or after that date and people who first became eligible through disability or ESRD. Most pages mention Plan F and forget Plan C. If you were Medicare-eligible before that date but had not enrolled, you may still qualify. In 2026 the high-deductible Plan F and Plan G deductible is $2,950, and the out-of-pocket limits are $8,000 for Plan K and $4,000 for Plan L.

How we handle it

We are independent, so we compare across carriers rather than selling one lineup. Using an agent costs you nothing extra. We check your actual doctors and your actual prescription list against each plan, because that is what determines whether a plan is cheap or expensive for you specifically. We map your enrollment windows so you do not trigger a lifetime penalty or lose your one shot at underwriting-free Medigap.

Official rules, current figures, and enrollment always live at Medicare.gov. Figures on this page are from the CMS 2026 Parts A and B fact sheet, the CMS Final CY 2026 Part D Redesign Program Instructions, and KFF, and are current as of August 3, 2026.

Written by Richard Sweet, licensed insurance advisor. Reviewed August 3, 2026. See our editorial process.