In 2025, roughly 1.5 million Medicare Advantage beneficiaries are losing their current coverage because insurers have exited markets or terminated specific plan contracts, triggering a federally defined Special Enrollment Period that gives affected enrollees a limited but meaningful window to find new coverage.
Why So Many Plans Are Leaving in 2025
The wave of Medicare Advantage exits in 2025 is the largest since the program's modern structure took shape under the Medicare Modernization Act of 2003. Several large insurers cited unsustainable medical-loss ratios driven by higher-than-projected utilization among older enrollees, combined with CMS benchmark payment adjustments finalized in the April 2024 rate notice. CMS reduced effective payment rates by approximately 0.16 percent in 2024 and made additional risk-score recalibrations that squeezed margins further in 2025. Smaller regional plans, which lack the administrative scale to absorb those changes, were disproportionately affected. The result is that beneficiaries in rural counties and certain Sun Belt markets face the fewest replacement options.
How CMS Notifies Affected Enrollees
Federal regulations require CMS to send a written notice to every beneficiary whose plan is being terminated. That notice must arrive no later than October 1 of the year before the termination takes effect. The letter identifies the termination date, explains the SEP, and lists a phone number for the Medicare helpline. CMS also posts a searchable list of terminated contracts on its website. If you received this letter and set it aside, retrieve it now — the contract number printed on it will help you verify your situation on Medicare.gov's Plan Finder tool.
The Special Enrollment Period: Exact Dates and Rules
Under 42 CFR 422.62(b)(2), a plan termination triggers an SEP that begins October 1 and ends February 28 of the following year. That means affected 2025 enrollees have until February 28, 2025, to make a coverage change. This window is separate from the standard Annual Enrollment Period, which runs October 15 through December 7 each year. You can use either period, but the SEP gives you additional time if you missed the AEP deadline.
During this SEP you may take one of three actions. First, you can enroll in a different Medicare Advantage plan — with or without drug coverage — that is available in your county. Second, you can return to Original Medicare and enroll in a standalone Part D prescription drug plan. Third, you can return to Original Medicare without a drug plan, though this is rarely advisable unless you have creditable drug coverage from another source such as a union retiree plan.
What Happens If You Do Nothing
If you take no action before your plan's termination date, CMS will auto-enroll you in Original Medicare Parts A and B. You will not automatically receive a Part D drug plan. Going without drug coverage for 63 days or more creates a late-enrollment penalty that is permanently added to your future Part D premiums, calculated as 1 percent of the national base beneficiary premium for each month without coverage. On a practical level, you will also lose any supplemental benefits — dental, vision, hearing, transportation — that your terminated MA plan provided.
Your Medigap Guaranteed-Issue Right
One of the most valuable and least-publicized protections in this situation is the guaranteed-issue right for Medigap. Under federal law, if you are returning to Original Medicare because your MA plan was terminated, insurers selling Medigap policies in your state must accept your application without medical underwriting for 63 days after your MA coverage ends. They cannot charge you a higher premium based on pre-existing conditions during this window. This right applies to Medigap Plans A, B, C, D, F (if you were eligible for Medicare before January 1, 2020), G, and K through N, depending on what is sold in your state.
After the 63-day window closes, insurers in most states can use medical underwriting, which means a history of diabetes, heart disease, or other chronic conditions could result in a higher premium or outright denial. Acting promptly is therefore financially significant.
How to Compare Replacement Plans
The Medicare Plan Finder at Medicare.gov allows you to enter your ZIP code, current medications, and preferred pharmacy to generate a side-by-side comparison of available plans. The tool displays the monthly premium, annual deductible, estimated annual drug costs, star rating, and out-of-pocket maximum for each option. CMS updates the tool each fall with the following year's plan data.
When reviewing plans, pay particular attention to the provider network. A plan may list your primary care physician as in-network but exclude the specialist or hospital you rely on. Call the plan directly to confirm network status for any provider you see regularly, and ask whether your current prior authorizations will transfer or need to be resubmitted.
Getting Help at No Cost
Every state has a State Health Insurance Assistance Program, known as SHIP, that provides free, unbiased counseling from trained volunteers. SHIP counselors do not sell insurance and have no financial stake in your decision. You can find your local SHIP contact through the SHIP National Technical Assistance Center or by calling 1-800-MEDICARE. For beneficiaries with limited income, the Medicare Savings Programs and the Low Income Subsidy for Part D — also called Extra Help — can significantly reduce premiums and cost-sharing. Applications for Extra Help are processed through the Social Security Administration.
Confirming Your New Coverage
After you select a new plan, do not assume the enrollment is complete until you receive written confirmation. Log in to your Medicare.gov account or call 1-800-MEDICARE to verify that your new plan appears as active. Keep a record of the confirmation number from your enrollment call. If your new plan card has not arrived by December 25, contact the plan directly using the number on Medicare.gov rather than waiting.