Medicare Advantage

What Chicago Enrollees Can Change During Medicare Advantage OEP

For 2027, Chicago is looking at 67 Medicare Advantage plans: 6 new, 17 gone since 2026, and 30 still here but changed on premium, deductible, plan type or name, 9 of them under a new name. Below, how the lineup shifted in Cook County and what to compare, with no plan ranked or recommended.

CHICAGO — If you signed up for a Medicare Advantage plan during fall enrollment and are already second-guessing that choice, you still have time to act. The Medicare Advantage Open Enrollment Period runs January 1 through March 31, and it is the last built-in chance most people will have to change course until next fall.

This window is easy to miss because it is quieter than the big October-to-December push. But for people already enrolled in a Medicare Advantage plan, it is a real do-over — with firm rules about who can use it and what can be changed.

What the January–March window actually is

The Medicare Advantage Open Enrollment Period (often called MA-OEP) is a yearly window set by the Centers for Medicare & Medicaid Services. It runs from January 1 through March 31 and exists so people who are already in a Medicare Advantage plan can fix a choice that is not working out.

It is not the same as the Annual Enrollment Period (AEP) that ended December 7. AEP is open to almost everyone with Medicare. The January–March window is narrower.

Who can use it — and who can't

You can use the Medicare Advantage Open Enrollment Period if, as of January 1, you are enrolled in a Medicare Advantage plan (with or without drug coverage).

You cannot use it if:

• You have Original Medicare only.
• You have Original Medicare plus a stand-alone Part D drug plan and want to switch drug plans.
• You want to join a Medicare Advantage plan for the first time from Original Medicare.

Those situations generally have to wait for the fall Annual Enrollment Period, unless a Special Enrollment Period applies (for example, if you move out of your plan's service area or lose other coverage).

What you can change — and what you can't

Between January 1 and March 31, you may:

• Switch from one Medicare Advantage plan to another Medicare Advantage plan.
• Drop your Medicare Advantage plan and go back to Original Medicare. If you do that, you can also join a stand-alone Part D prescription drug plan.

You may make only one change during this window. Once your new plan processes the request, that is it until fall — barring a qualifying life event.

Coverage from your new choice starts the first day of the month after the plan receives your enrollment. So a switch made in February takes effect March 1; a switch made March 31 takes effect May 1.

How the dates fit together

It helps to picture the Medicare calendar as three layers:

• October 15 – December 7 (Annual Enrollment Period): Anyone with Medicare can join, switch, or drop a Medicare Advantage or Part D plan. Changes take effect January 1.
• January 1 – March 31 (Medicare Advantage Open Enrollment): A one-time reset, but only for people already in a Medicare Advantage plan.
• Special Enrollment Periods: Triggered by specific life changes — moving, losing employer coverage, qualifying for Extra Help, and others. Rules and timing vary.

There is also a separate Medigap (Medicare Supplement) landscape with its own rules; leaving Medicare Advantage does not automatically guarantee you can buy any Medigap plan you want, so it is worth asking about medical underwriting before you drop coverage.

If you miss March 31

If March 31 passes without action, your current Medicare Advantage plan stays in place for the rest of the year. Your next regular chance to change plans will be the fall Annual Enrollment Period, October 15 – December 7, for coverage starting January 1, 2028.

The exception is a Special Enrollment Period. Common triggers include:

• Moving to a new address that is outside your plan's service area, or that gives you new plan options.
• Losing other creditable coverage, such as an employer or union plan.
• Becoming eligible for Medicaid or the Extra Help program for drug costs.
• Your plan leaving Medicare or changing its contract.

Chicago is in Cook County, where a large number of Medicare Advantage plans are offered — so a local move, even within the metro area, can sometimes change what is available to you and open a Special Enrollment Period. Ask before you assume.

A few things worth checking before you switch

Before you use your one change, take a few minutes to:

• Re-read the plan materials you received in the fall — the "Evidence of Coverage" and the "Annual Notice of Change." Sometimes the discomfort with a new plan is about a change you did not notice.
• Check the provider directory. Confirm your doctors, hospitals and preferred pharmacies are in-network for any plan you are considering.
• Check the drug formulary. Make sure your prescriptions are covered and note any prior-authorization or step-therapy requirements.
• Think about Part D on its own. If you are moving back to Original Medicare, remember that the Part D out-of-pocket cap is $2,100 in 2026 and $2,400 in 2027, and the maximum Part D deductible is $615 in 2026 and $700 in 2027. The Medicare Prescription Payment Plan also lets you spread drug costs across the year in monthly installments if that helps your budget.

Where to get unbiased help

For personalized questions, use the official channels:

• Medicare.gov — the Plan Finder lets you compare Medicare Advantage and Part D options in your ZIP code.
• 1-800-MEDICARE (1-800-633-4227) — available 24/7.
• Illinois SHIP (Senior Health Insurance Program) — free, one-on-one counseling from trained volunteers who do not sell insurance. Reach it through the Illinois Department on Aging.