How we work out each answer

Last updated October 4, 2026

In plain words

Every year, CMS (the Centers for Medicare & Medicaid Services, the federal agency that runs Medicare) publishes a list of every Medicare Advantage and Part D plan, and the counties where each one is offered. We compare the 2026 list with the 2027 list.

• If your plan is on both lists for your county, it is offered in 2027.
• If it is on the 2026 list but not the 2027 list for your county, it is not offered in 2027.
• If it is gone, but the same company has a plan with the same name and a new number in your county, we say it is probably being replaced.

We never change CMS data by hand. Every answer comes from the CMS files listed below.

The details

Sources

• Source: CMS CY2027 Landscape, data as of September 22, 2026 (release 202609.1).
• Source: CMS CY2026 Landscape, data as of September 2, 2026 (release 202609).
• Enrollment: CMS Monthly Enrollment by Contract/Plan/State/County, September 2026.
• ZIP code to county: HUD-USPS ZIP Code Crosswalk (HUD Office of Policy Development and Research), 2026 second quarter, using each ZIP's share of homes. The U.S. Census Bureau 2020 ZIP-area (ZCTA) to county file fills gaps and is used for Connecticut.
• County names and codes: U.S. Census Bureau 2020 county list, plus the CMS enrollment file.

The tables on this site are derived from these files by us. The government agencies that publish the files have not reviewed or endorsed them. We keep a copy of every CMS file version we use.

The six results and how each one shows

We look at each plan in each county. Each one gets one of six results, checked in this order:

1. Continues. The same plan, with the same number, is offered in your county in 2027. Shows as "Your plan is offered in [County] in 2027."
2. Continues, new segment number. Some plans are split into parts called segments. The plan is still offered in your county, but its segment number changed. Shows as "offered," with a note to check your Annual Notice of Change because benefits may differ.
3. Probably being replaced. Your plan's number is gone, but the same company offers a plan with the same name and a new number in your county. Shows as "Your plan is probably being replaced by a plan with a new number," with both plans side by side.
4. Not offered: company leaving. The company's whole contract (a group of plans) ends everywhere in 2027. Shows as "Your plan will not be offered in 2027."
5. Not offered: plan discontinued. The company still offers other plans in your county, but not this one. Shows as "Your plan will not be offered in 2027."
6. Not offered: left your county. The company still operates elsewhere, but not this plan in your county. Shows as "Your plan will not be offered in [County] in 2027." For Part D plans, this is "left your state."

For the three "not offered" results, we also show what happens if you do nothing, your sign-up windows, and other rights that apply.

Why "probably being replaced" is our own match

Sometimes a company ends a plan number and moves its members into a new plan with the same name. CMS publishes a "plan crosswalk" file that says exactly which old plan moves into which new plan. CMS usually posts it in October, and the 2027 file is not out yet.

Until then, we match plans by company and plan name. This is our own match, not a CMS statement, so we say "probably." When CMS posts the crosswalk, we will switch to it, and these answers will become a firm "offered" or "not offered."

The national numbers, explained

These counts are for Medicare Advantage plans. Each count is one plan in one county (a "plan-county row").

Our main number is the last one: 28,173 plan-county rows not offered in 2027. We show the 3,527 rows that are probably being replaced as a separate number. We never add them into the main number, because those members may be moved into a new plan.

Part D (drug-only) plans are counted on their own: 122 plan-state rows not offered in 2027.

Part D plans are offered statewide

Stand-alone Part D drug plans are offered across a whole state, not county by county. So for these plans, "your county" becomes "your state," and a Part D plan can only leave a state.

How many people are affected

We use the CMS enrollment file to count how many people are in each plan. CMS hides counts of 10 or fewer people to protect privacy. We show those as "10 or fewer," never as a number. Because of that, our totals are "at least" figures.

Around the site, we round these counts, for example "~22,000" or "about 5,100 people." They come from a single month, leave out hidden small counts, and some plans counted as "not offered" may turn out to be moving their members into another plan, so an exact figure would look more certain than it is. The exact source figures are below and in every CSV download.

• At least 4,496,334 people are in Medicare Advantage plans that won't be offered in their county in 2027.
• At least 781,798 more are in Medicare Advantage plans that are probably being replaced.
• At least 2,522,569 people are in Part D plans that won't be offered in their state in 2027.

Enrollment: CMS Monthly Enrollment by Contract/Plan/State/County, September 2026. Plans not found in the enrollment file are counted as 0.

ZIP codes that cross county lines

Some ZIP codes cover more than one county. When that happens, we ask which county you live in. The county with the most homes in that ZIP is listed first.

Premiums with Extra Help

Extra Help is a Medicare program that lowers drug costs for people with limited income. If you turn on "I get Extra Help," we show a different monthly premium. It is the plan's medical (Part C) premium plus the drug premium CMS lists for people with Extra Help. For drug-only plans, it is just that drug premium. With Extra Help, the drug deductible is $0. Plans without drug coverage don't change.

Out-of-pocket limits for D-SNPs

D-SNPs are plans for people who have both Medicare and Medicaid. We don't show a dollar out-of-pocket limit for these plans. With Medicaid, most of your costs are covered, and what you pay depends on your Medicaid level. Medicare Plan Finder doesn't show a dollar figure for these plans either.

Star ratings

CMS has not yet added 2027 star ratings to its plan data file. CMS expects to post them on Medicare.gov on or around October 8, 2026. They will show here once CMS adds them to its file. Until then, plans show "Not yet rated by CMS."

How often we update

CMS often posts corrected versions of its files in the fall. When CMS posts a new version, we rebuild the site from it. Every page shows the CMS file version and its date, so you can see which data you are looking at.

How we checked our work

On October 4, 2026, we compared our results for ZIP code 92660 (Orange County, California) with Medicare Plan Finder. All 111 plans Plan Finder listed for 2027 matched our list, with the same plan IDs.

Found a mistake?

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