Medicare Advantage

What’s Changing in Missouri Medicare Advantage for 2027: 21 Plans Leaving, 42 Changing

JEFFERSON CITY — Missouri's Medicare Advantage lineup is shifting again for the 2027 plan year, and every one of the state's 115 counties will see at least one plan leave or change, according to the Centers for Medicare & Medicaid Services (CMS) MA Landscape files for 2026 and 2027. The two files, read side by side, show that 157 Medicare Advantage plans were offered somewhere in Missouri for 2026 and 174 will be offered for 2027. Of the plans available this year, 21 are leaving the state entirely, 42 are returning with at least one change on file, and 94 are continuing unchanged. Another 38 are new.

For members, the practical window is the Annual Enrollment Period, October 15 through December 7, 2026. A choice made in that window takes effect January 1, 2027. Here is what the numbers mean, and what to do if you are in a plan that is leaving or changing.

What the statewide numbers mean

CMS publishes a Landscape Source File each fall listing every Medicare Advantage plan offered in each county. Comparing the 2026 and 2027 files, each plan counted once statewide no matter how many counties it covers, produces the figures above: 157 plans for 2026, 174 for 2027, with 21 leaving, 42 changing, 38 new, and 94 continuing unchanged.

In CMS's file, a plan is "leaving" if it was offered somewhere in Missouri for 2026 and is offered nowhere in Missouri for 2027. A plan is "changing" if it is offered in both years but differs in at least one county on premium, drug deductible, plan type, or plan name. "Continuing unchanged" means none of those four fields moved between the two files. The Landscape file does not describe benefits in detail; your plan's Annual Notice of Change (ANOC), mailed by the end of September, is the document that spells out specifics for 2027.

One carrier appears in the 2026 Missouri file but not in the 2027 file: Healthy Blue.

If your plan is leaving

If your 2026 Medicare Advantage plan is among the 21 not returning anywhere in Missouri, CMS gives you a Special Enrollment Period (SEP) that runs through the end of February 2027. During that SEP you can enroll in another Medicare Advantage plan or move back to Original Medicare and, if you choose, add a stand-alone Part D prescription drug plan.

You should receive a non-renewal notice from your current carrier. If you take no action, coverage under the ending plan stops, and in most cases you would return to Original Medicare on January 1, 2027 without drug coverage until you make a new election. Acting during the Annual Enrollment Period, October 15 to December 7, 2026, keeps your coverage continuous on January 1.

If your plan is changing

Forty-two Missouri plans are returning for 2027 with at least one change recorded in CMS's file. The ANOC your carrier sends is the authoritative document; it lists every change your plan is making for 2027 and compares it to 2026 side by side. Read it in full, including the sections on provider networks and drug formularies, which can shift even when a plan name does not.

A member who does nothing stays enrolled in a renewing plan under its 2027 terms as described in the ANOC. If after reading the notice the plan no longer fits, the Annual Enrollment Period is the time to switch; a new election made by December 7, 2026 takes effect January 1, 2027.

The counties with the most change

All 115 Missouri counties see at least one plan leave or change for 2027. The counties with the highest counts in the CMS files are:

• Jefferson County: 10 leaving, 24 changing
• St. Charles County: 10 leaving, 24 changing
• St. Louis City: 10 leaving, 24 changing
• St. Louis County: 10 leaving, 24 changing
• Crawford County: 10 leaving, 23 changing
• Warren County: 10 leaving, 22 changing
• Washington County: 10 leaving, 22 changing
• Clay County: 11 leaving, 20 changing

These are county-level counts drawn from the Landscape files. A plan may appear on more than one county's list because Medicare Advantage plans are offered county by county.

What to do before December 7

A short checklist for Missouri members this fall:

1. Watch the mail in September and early October for either an ANOC (plan is renewing) or a non-renewal notice (plan is leaving). Keep both. 2. Make a current list of your doctors, hospitals, and prescriptions, including dosages. 3. If your plan is renewing, read the ANOC and confirm your providers and drugs are still covered for 2027. 4. If your plan is leaving, note that your SEP runs through the end of February 2027, but acting during the Annual Enrollment Period keeps coverage continuous on January 1, 2027. 5. Compare options on Medicare.gov's Plan Finder, which draws on the same CMS Landscape and Plan Finder data. 6. Make any change by December 7, 2026 for a January 1, 2027 effective date.

Where to get free help

You do not have to work through this alone, and you do not have to pay anyone to help you.

• Medicare.gov — the official federal site, with the Plan Finder tool for comparing 2027 Medicare Advantage and Part D options in your ZIP code.
• 1-800-MEDICARE (1-800-633-4227) — 24 hours a day, seven days a week, with TTY service available.
• Missouri's State Health Insurance Assistance Program (SHIP), known locally as CLAIM — free, one-on-one counseling from trained volunteers who do not sell insurance.