One of the most common calls I get from existing Medicare Advantage enrollees in the Kansas City area goes something like this: “I hate my plan but I don’t know if I’m allowed to change it right now.” The answer surprises most people — there are actually four different windows when you can change your Medicare Advantage coverage, and most people only know about one of them.
Here’s a complete guide to every enrollment period that applies to Medicare Advantage enrollees in Missouri and Kansas.
What Is the Annual Enrollment Period for Medicare Advantage?
The Annual Enrollment Period — AEP — runs October 15 through December 7 every year. This is the main Medicare enrollment window that gets the most advertising attention, and for good reason. During AEP, any Medicare beneficiary can make any of the following changes:
Switch from one Medicare Advantage plan to another. Drop Medicare Advantage and return to Original Medicare (with or without a Medigap supplement and Part D plan). Switch from Original Medicare to Medicare Advantage. Change their standalone Part D drug plan.
Changes made during AEP take effect January 1 of the following year. This is the window I’m busiest in — I review every existing client’s plan during October and November to identify whether their current plan still makes sense for the coming year. Networks change, formularies change, and premiums change annually. The plan that was the best choice in 2025 may not be the best choice in 2026.
For Kansas City area residents on both sides of the state line — whether you’re in Jackson County Missouri or Johnson County Kansas — AEP applies the same way. Mark October 15 on your calendar every year.
What Is the Medicare Advantage Open Enrollment Period?
The Medicare Advantage Open Enrollment Period — OEP — runs January 1 through March 31 every year. This is the lesser-known enrollment window that most Medicare Advantage enrollees don’t know exists.
During OEP, anyone already enrolled in a Medicare Advantage plan can make one change: switch to a different Medicare Advantage plan, or drop Medicare Advantage and return to Original Medicare. You cannot use OEP to switch from Original Medicare to Medicare Advantage — it’s only available to people already on an Advantage plan.
Changes made during OEP take effect the first day of the month after your request is processed. So if you switch plans in February, your new coverage starts March 1.
OEP is valuable for Kansas City area residents who enrolled in a Medicare Advantage plan during AEP and quickly realized it wasn’t working — maybe their doctor isn’t in the network, the drug formulary doesn’t cover their medications, or they had an unexpected medical event in January that made them reconsider their coverage. OEP gives you a second chance to correct that decision before being locked in for the rest of the year.
One important limitation: if you drop Medicare Advantage during OEP and return to Original Medicare, you are not automatically entitled to Medigap guaranteed issue rights in Missouri or Kansas. You’ll likely face medical underwriting if you want a Medigap supplement — unless you qualify for one of the specific guaranteed issue situations.
What Are Special Enrollment Periods for Medicare Advantage?
Special Enrollment Periods — SEPs — allow you to change your Medicare Advantage coverage outside of AEP and OEP when certain qualifying life events occur. SEPs are event-driven, not calendar-driven, and each has specific rules about timing and what changes are permitted.
The most common SEPs for Kansas City area Medicare Advantage enrollees include:
Moving outside your plan’s service area. If you move to a new address that’s outside your current plan’s coverage area, you have a SEP to enroll in a new plan. This is particularly relevant for KC metro residents who move across the state line — from Missouri to Kansas or vice versa — since state boundaries separate Medicare plan marketplaces. Moving from Blue Springs to Overland Park triggers a SEP because you’ve moved from a Missouri plan area to a Kansas plan area.
Your plan leaves your area or stops covering your area. If your Medicare Advantage carrier exits your county or terminates your plan, you have a SEP to choose a new plan. This happens periodically when carriers decide to stop offering plans in certain markets.
You qualify for Extra Help (Low-Income Subsidy). If you newly qualify for the Extra Help program for Part D costs, you gain a SEP to change plans. This SEP is available once per quarter for the first three quarters of the year.
Your plan loses its Medicare contract. If your Medicare Advantage plan loses its contract with CMS, you receive a SEP to choose alternative coverage.
Five-star plan SEP. If a Medicare Advantage plan in your area earns a 5-star quality rating from CMS, you can switch to that plan once between December 8 and November 30 of the following year. This SEP is available once per year and doesn’t require any qualifying event beyond the plan having a 5-star rating.
Moving into or out of a long-term care facility. Entering or leaving a skilled nursing facility, nursing home, or other long-term care facility triggers a SEP.
What Is the Trial Right for New Medicare Advantage Enrollees?
The trial right is one of the most valuable and least-known protections in Medicare — and it applies specifically to people in their first year of Medicare Advantage enrollment.
If you enrolled in Medicare Advantage for the first time and decide within that first year that you want to return to Original Medicare with a Medigap supplement, you have a guaranteed issue right to purchase a Medigap plan. The Medigap carrier cannot deny you or charge you more based on health history — even if you’ve developed conditions during the year.
This trial right exists because Congress recognized that new Medicare beneficiaries sometimes make plan choices without fully understanding the implications. The first-year escape hatch allows you to try Medicare Advantage and return to Medigap with full protections if it doesn’t work for you.
After the first year, this protection disappears. If you’re in your second or third year of Medicare Advantage and want to switch to Medigap in Missouri or Kansas, you’ll face medical underwriting. I’ve worked with Lee’s Summit and Independence clients who didn’t know about the trial right until it was too late — and found themselves unable to get Medigap coverage at standard rates because of health conditions that developed after year one.
If you’re in your first year of Medicare Advantage and having second thoughts, call me before that year is up.
What Happens If You Miss All the Enrollment Windows?
If you’re outside all enrollment windows — past OEP, not in a SEP, and AEP hasn’t started yet — you’re generally locked into your current Medicare Advantage plan until the next enrollment opportunity.
This is one of the most frustrating situations I encounter with Kansas City area clients. Someone has a bad experience with their plan in June — a denied claim, a surprise out-of-pocket cost, a doctor leaving the network — and calls me wanting to switch immediately. Without a qualifying SEP, the options are limited until AEP opens in October.
The practical advice: if something changes with your plan or your health situation mid-year, call me immediately. I can assess whether any SEP applies to your situation and help you take action if a window exists. Don’t wait until October only to discover you had a SEP available in July that you missed.
How Does This Apply Differently in Missouri vs Kansas?
The enrollment periods themselves — AEP, OEP, SEP — are federal Medicare rules that apply identically in both Missouri and Kansas. The differences between the two states show up in plan availability and Medigap rules.
Missouri and Kansas have separate Medicare Advantage plan marketplaces. When you move across the state line, you’re entering a new plan market and triggering a SEP. The plans available in Johnson County, Kansas are different from the plans available in Jackson County, Missouri — different carriers, different networks, different premiums.
For Medigap, Missouri and Kansas both allow medical underwriting outside of guaranteed issue periods — so the trial right and open enrollment window protections apply in both states, but the underwriting risk if you miss those windows exists in both states as well.
KC metro residents near the state line — in communities along both sides of the border — should be especially aware of how moving affects their Medicare Advantage coverage, and should call me before any planned relocation to make sure coverage transitions smoothly.
When Should Kansas City Area Residents Review Their Medicare Advantage Plan?
I recommend reviewing your Medicare Advantage plan every year during October and November, before AEP closes on December 7. Here’s what I look for in every annual review:
Did your doctors and specialists remain in-network? Networks change annually and your provider may have left the plan’s network without you knowing.
Did your medications stay on the formulary at the same tier? Drug formularies change every year. A medication that was a Tier 2 copay in 2025 may be Tier 3 or Tier 4 in 2026.
Did your plan’s out-of-pocket maximum change? The maximum exposure you carry can increase year over year.
Did better options become available in your ZIP code? New plans enter the market annually and existing plans change their benefits.
I do this review for every active client in my practice — reaching out each fall to flag any changes that warrant a switch. If you’re not currently working with an independent advisor who does this for you, call me at 816-291-3655. It’s free and it takes about 20 minutes.
Frequently Asked Questions
Can I switch Medicare Advantage plans at any time in Missouri or Kansas?
No — you can only switch during specific enrollment windows. The Annual Enrollment Period (Oct 15–Dec 7) is the main window. The Medicare Advantage Open Enrollment Period (Jan 1–Mar 31) allows one switch for existing Advantage enrollees. Special Enrollment Periods are available for qualifying life events. Outside these windows you’re generally locked into your current plan.
What is the difference between AEP and OEP for Medicare Advantage?
AEP (Oct 15–Dec 7) is open to all Medicare beneficiaries and allows any plan change. OEP (Jan 1–Mar 31) is only for people already enrolled in Medicare Advantage and allows one switch — either to a different Advantage plan or back to Original Medicare. You cannot use OEP to switch from Original Medicare to Medicare Advantage.
Can I switch Medicare Advantage plans if I move from Kansas City MO to Overland Park KS?
Yes — moving across the state line is a qualifying Special Enrollment Period event. You’ll need to enroll in a Kansas plan since your residence address determines your plan marketplace. I help KC metro clients navigate these transitions and find the best available plan in their new county.
What happens to my Medicare Advantage plan during the Annual Enrollment Period if I do nothing?
Your plan automatically renews for the following year unless you make a change or your plan exits your market. However, your plan’s benefits, network, formulary, and premium may all change even if you do nothing. Passive renewal does not mean your coverage stays the same — it means you’re enrolled in whatever your current plan becomes in the new year.
Is there a penalty for switching Medicare Advantage plans?
No — there is no penalty for switching Medicare Advantage plans during a valid enrollment period. You simply enroll in the new plan and your old plan coverage ends. The only penalty risk in Medicare is the Part B and Part D late enrollment penalties for delaying enrollment without qualifying coverage — not for switching between plans.