How to Disenroll from a Medicare Advantage Plan When Coverage Fails

The Annual Notice of Change came in a window envelope on September 30. Forty-two pages. The cover sheet listed the 2026 premium ($0), the deductible ($0), the maximum out-of-pocket ($5,900), and a single phrase in bolder type than the rest: Some Benefits Are Changing. The 71-year-old retired accountant in St. Petersburg who had been on the same Medicare Advantage plan since 2020 set it on a stack of mail and forgot it. In late November his cardiologist's office called to schedule a follow-up echocardiogram and mentioned, in passing, that as of January 1 the practice would no longer be in the plan's network. He pulled the booklet back out. The hospital his cardiologist admitted at had also exited. The plan's 2026 formulary had moved his daily anticoagulant from Tier 2 to Tier 4. The MOOP had risen by $1,800. None of these changes alone would have triggered a Special Enrollment Period. Read together, the booklet was telling him that the plan he had carried for five years no longer fit. The question on his kitchen table in early December was the one most MA beneficiaries do not learn to ask until they need to: what are the actual paths off this plan, and which one was still open in the calendar between then and the end of the year.

The paths are real and underused. KFF analyses of MA enrollment have found that among beneficiaries reporting significant coverage problems, only a fraction attempt disenrollment in any given year. The trial-right rules, the SEP framework, the five-star switching right, and the MA Open Enrollment Period together create a calendar with more open doors than most beneficiaries realize. The hard work is identifying which one applies and walking through it before it closes.

The five disenrollment paths, in order

Each runs on its own clock and produces a different downstream coverage structure.

The first is the MA Open Enrollment Period (MA-OEP) at 42 CFR 422.62(a)(3). January 1 through March 31. A beneficiary already enrolled in an MA plan may make one change: switch to a different MA plan, or disenroll back to Original Medicare and add a stand-alone Part D plan.

The second is the Annual Election Period (AEP) at 42 CFR 422.62(a)(2). October 15 through December 7, effective January 1. AEP is the only window in which any beneficiary can make an unrestricted plan change. Most disenrollments happen here by default.

The third is a Special Enrollment Period (SEP) at 42 CFR 422.62(b). SEPs are triggered by qualifying events: a move out of the plan's service area, loss of other creditable coverage, a change in Medicaid or Extra Help eligibility, a CMS-sanctioned plan, an institutional placement, and several narrower triggers. The CMS Medicare and You handbook lists the full set, updated annually. SEP windows vary, most commonly two months from the qualifying event.

The fourth is the MA trial right at 42 CFR 422.62(a)(4) and 42 USC 1395ss(s)(3). A beneficiary who joins MA when first eligible for Medicare and disenrolls within 12 months may return to Original Medicare with guaranteed-issue Medigap, without medical underwriting. The same trial right applies to a beneficiary who dropped a Medigap policy to try MA for the first time and disenrolls within 12 months. This is one of the most valuable and under-known protections in the framework.

The fifth is the 5-star SEP at 42 CFR 422.62(a)(8). A beneficiary may switch into a 5-star MA or Part D plan once per year between December 8 and November 30, where one is offered in the service area. CMS publishes the star-ratings list each fall.

A sixth path, the exceptional-circumstances SEP at 42 CFR 422.62(b)(3), is granted at CMS or plan discretion and is not a path the beneficiary controls.

The downstream coverage question

Disenrolling is half the move. The other half is what the beneficiary lands in: Original Medicare (Parts A and B) with a stand-alone Part D plan, or another MA plan.

The Original Medicare path requires three coordinated pieces. Parts A and B are automatic on MA disenrollment. The Part D plan must be elected in the same window. Medigap, the supplemental policy that closes most of Original Medicare's cost-sharing gaps, is the third and the one that produces the most planning errors.

Medigap is not automatic. It is an underwritten product sold by private insurers under state regulation. A beneficiary outside the federal guaranteed-issue windows (initial Medicare enrollment, the MA trial right, certain involuntary loss-of-coverage events, certain state-specific protections) faces medical underwriting and can be denied or rated for pre-existing conditions. Connecticut, Maine, Massachusetts, and New York have state laws providing year-round or annual guaranteed-issue Medigap; the protections and definitions vary, and verifying against current state DOI guidance is essential.

The MA-to-MA switch is simpler. The new MA plan replaces the old; Part D is built in. The trade-off is that the new plan carries its own network, formulary, and PA rules. The pattern that produced the original disenrollment can repeat.

When disenrollment is the right move and when it is not

Three patterns hold up after the fact.

Network failure: the plan's network has lost the providers and facilities the beneficiary needs. The fix is MA-OEP, AEP, or the move SEP where the beneficiary is also moving. Before disenrolling, Apellica often appeals the network-adequacy gap under the plan's own access standards.

Formulary failure: a medication has moved tier, been removed, or been added to step therapy or quantity limits. The first move is a formulary exception under 42 CFR 423.578; where denied, the disenrollment windows apply. The 5-star SEP can help when a 5-star plan covers the medication on a lower tier. Apellica handles the formulary-exception appeal for any beneficiary who would rather fight the change than switch plans.

Denial-rate failure: the plan's pattern of denials and delays, including issues documented in HHS OIG OEI-09-18-00260, has rendered coverage practically unusable. MA-OEP and AEP are the windows. A parallel complaint to the state DOI and CMS creates a documentation trail.

Three patterns the beneficiary often regrets.

Premium-driven switch without attention to MOOP: a $0-premium plan with a $7,500 MOOP costs less than a $50/month plan with a $4,000 MOOP only at very low utilization. The Plan Finder at medicare.gov is the comparison tool.

Disenrollment back to Original Medicare without a Medigap analysis: a beneficiary leaving MA after five years is outside the federal guaranteed-issue window and, in most states, faces underwriting that can decline or rate her based on chronic conditions. A failed Medigap application leaves her on Original Medicare without supplement and with substantial out-of-pocket exposure.

MA-to-MA switch without confirming network: the new plan's directory is the operative document; printed directories lag actual network and should be verified by direct call before the switch closes.

Why fighting the coverage failure is often harder than disenrolling, and why it usually pays better

Switching plans is a calendar exercise. Reversing the specific denial that drove the dissatisfaction (network exit, formulary tier change, repeated PA denial) is a procedural exercise governed by the mapped library Apellica has catalogued (more than two hundred carrier-by-denial-type cells, indexed at the bulletin level), the indexed Administrative Law Judge precedent library covering Medicare Advantage Subpart M appeals, and the formulary-exception framework at 42 CFR 423.578 and 42 CFR 423.584. The 30-day document-request right requires demand letters with the correct CFR cite.

The trade-off is real. A beneficiary who appeals successfully keeps the providers she has built relationships with, keeps the formulary tier she had, and gets the plan-level reversal on file as a deterrent against future denials. A beneficiary who disenrolls and changes plans gets a fresh network and formulary that may or may not solve the same problem six months later. For the right denials, the appeal is the better move; for the right beneficiaries, the switch is. The two are not substitutes, and the decision needs an honest review of the underlying denial pattern.

Disenrollment closes a door. The denial that drove the beneficiary to the door is still standing on the other side.

What separates a desk-prepared appeal from a self-prepared one

Apellica's review desk indexes carrier behavior across more than two hundred carrier-by-denial-type cells that tracks Medicare Advantage denial patterns at every major plan. The desk maintains the indexed Administrative Law Judge precedent library and the current formulary-exception caselaw under 42 CFR 423.578.

Same-day document-request letters go out with the correct CFR cite. Apellica's senior reviewers build the four-part evidence stack for every appeal, plan-language citation, clinical facts, peer-reviewed evidence, regulatory hook. A senior reviewer reads every appeal before it goes out. Disenrollment and enrollment decisions are not part of the desk's scope; SHIP and the Medicare Rights Center handle those.

Initial review of the underlying denials is free. There is no upfront fee. Beneficiaries are not asked to pay anything until the carrier reverses the denial.

Exhibit 1: The five disenrollment windows

Action title: A beneficiary unhappy with a Medicare Advantage plan is rarely stuck. The calendar has at least one open door at any given moment of the year; the work is identifying which one applies.

| Window | Period | Eligibility | Reg cite | |---|---|---|---| | Annual Election Period (AEP) | October 15 - December 7 | All MA beneficiaries | 42 CFR 422.62(a)(2) | | MA Open Enrollment Period (MA-OEP) | January 1 - March 31 | Already-enrolled MA beneficiaries, one change | 42 CFR 422.62(a)(3) | | 12-month trial right | First 12 months on MA when first eligible | First-time MA enrollees | 42 CFR 422.62(a)(4); 42 USC 1395ss(s)(3) | | 5-star SEP | December 8 - November 30 | Available where a 5-star plan exists | 42 CFR 422.62(a)(8) | | SEP for qualifying events | Varies by trigger (typically 2 months) | Move, loss of coverage, dual-eligibility change, etc. | 42 CFR 422.62(b) |

Exhibit 2: The downstream-coverage decision tree

Action title: The decision is not "leave the plan." The decision is "leave the plan and land where, with which supplements, at which cost, with which underwriting risk."

| Path | Pros | Cons | Underwriting risk | |---|---|---|---| | Original Medicare + Part D + Medigap (in trial-right window) | Broadest provider access; predictable cost-sharing with Medigap | Two premiums (Part D + Medigap); requires active selection | None during trial-right window | | Original Medicare + Part D + Medigap (outside trial-right) | Same coverage profile | Same plus Medigap underwriting | Significant in most states; minimal in CT, ME, MA, NY | | Original Medicare + Part D, no Medigap | Lower premium | Substantial out-of-pocket exposure on hospitalization | None on Medicare itself | | Switch to different MA plan | Single enrollment, single premium structure | Network and formulary risk repeats | None on MA enrollment |

Exhibit 3: The disenrollment-mechanics checklist

Action title: The mechanical steps are simple. The hard step is doing them in the right order. Disenrollment is effective the first day of the month after the change is processed; the timing question controls the gap-coverage question.

| Step | What to do | Timing | |---|---|---| | Confirm the window | Identify which of the five paths is open | Before any action | | Select downstream coverage | Original Medicare with Part D and Medigap, or new MA plan | Before disenrollment | | Enroll in new coverage | The new enrollment automatically disenrolls the old MA plan in most cases | Same window | | Confirm effective dates | First day of the following month, except for AEP (January 1) | At enrollment | | Confirm provider network and formulary | Direct call to each major provider and pharmacy | Before effective date | | Notify providers and pharmacy of new coverage | Provide new ID card or plan information | At effective date |

Where the regulations help and where they do not

The trial-right rule at 42 CFR 422.62(a)(4) is the single most valuable consumer protection in the disenrollment regime. It provides a 12-month off-ramp back to Original Medicare with guaranteed-issue Medigap. Beneficiaries inside their first MA year who are dissatisfied should evaluate the trial-right move before any other path.

The 5-star SEP at 42 CFR 422.62(a)(8) is useful where 5-star plans exist and not where they do not. The CMS-published star ratings show 5-star MA plans concentrated in a relatively small number of metropolitan markets and regional integrated systems; verify against the current file before relying.

The exceptional-circumstances SEP at 42 CFR 422.62(b)(3) is at CMS or plan discretion. Occasionally useful as escalation, not a planning tool.

The Medigap underwriting question, in plain numbers

A beneficiary leaving MA outside the trial-right window faces medical underwriting on most Medigap policies in most states. Common chronic conditions, diabetes with complications, heart failure, COPD, prior stroke, recent serious treatment, frequently produce declines or rate-ups in the 25 to 100 percent range.

Four states, Connecticut, Maine, Massachusetts, and New York, provide guaranteed-issue Medigap to varying degrees outside the federal windows. California provides a birthday-rule annual window allowing switching among Medigap policies of equal or lesser benefit without underwriting. Confirm the rule that applies with the state DOI before relying.

A beneficiary who disenrolls back to Original Medicare without an issued Medigap policy in hand has coverage but no supplement. Exposure on a single hospitalization is meaningful: the Part A deductible is $1,676 per benefit period (CY 2026, verify with current CMS source), with inpatient coinsurance applying for days 61 and beyond. The decision to leave MA without a Medigap policy in hand is recoverable only at the next AEP.

Where to ask for help

Every state operates a State Health Insurance Assistance Program (SHIP) under Administration for Community Living funding, with free counselors. Directory at shiphelp.org. The Medicare Rights Center at medicarerights.org runs a hotline at 800-333-4114. The Center for Medicare Advocacy at medicareadvocacy.org publishes guidance on trial-right, SEP, and Medigap questions. The Medicare Plan Finder at medicare.gov is the authoritative tool for plan-to-plan comparison.

The state DOI handles Medigap underwriting and state guaranteed-issue rules. The NAIC consumer site at content.naic.org/consumer.htm lists every state contact.

Apellica, at apellica.com, prepares appeal letters for MA denials. Disenrollment is not an appeal; Apellica does not handle enrollment.

What to do if you are considering disenrollment right now

The Annual Notice of Change is a planning document, not a coverage warning. Before disenrolling, look at whether the specific denials, network exits, or formulary changes can be appealed. Many can.

Most beneficiaries leave coverage on the table because the appeal that would have kept their providers and their formulary tier is more procedural work than they can take on.

The St. Petersburg accountant filed a Tier 4 formulary exception under 42 CFR 423.578 in mid-December. The exception cleared in fourteen days, restoring his anticoagulant to Tier 2 cost-share. He stayed on the plan, kept his cardiologist by switching to a different in-network admitting hospital, and made no MA Open Enrollment switch.

How the desk takes on a case

Apellica prepares evidence-based appeal letters for Medicare Advantage denials at every level of the federal appeals process under 42 CFR Part 422 Subpart M. The patient reviews and approves every word before submission and authorizes carrier communications under a HIPAA-compliant Assignment of Benefits. We are not a law firm, medical provider, or insurance carrier.

Our model is $0 upfront and a flat fee on successful recovery. Coverage in all 50 states. A senior reviewer reads every case. Disenrollment and enrollment decisions are not part of our scope; we route beneficiaries to SHIP and the Medicare Rights Center.

About the author

About the author. Mark Henderson is a senior reviewer at Apellica, an independent appeal-preparation service for denied health-insurance claims. The office is at One World Trade Center, Suite 8500, New York, NY 10007. Apellica covers all fifty states. Apellica does not provide legal advice and is not a law firm. For questions: press@apellica.com, +1 (888) 777-6120, apellica.com.

References

• 42 CFR 422.62. Election of coverage under an MA plan (subsections (a)(2), (a)(3), (a)(4), (a)(8), (b), (b)(3)).
• 42 USC 1395ss(s)(3). Medigap guaranteed-issue protections.
• 42 CFR 423.578. Formulary exceptions (Part D).
• CMS, Medicare and You 2026 handbook (current edition).
• CMS, Star Ratings for Medicare Advantage and Part D plans, annual file (2026 verification).
• HHS Office of Inspector General, OEI-09-18-00260.
• KFF, MA enrollment and dissatisfaction analyses, 2024-2025.
• Medicare Rights Center. medicarerights.org. Hotline 800-333-4114.
• SHIP. shiphelp.org.
• Center for Medicare Advocacy. medicareadvocacy.org.
• Medicare Plan Finder. medicare.gov.
• NAIC Consumer Information Source. content.naic.org/consumer.htm.
• State Medigap guaranteed-issue laws: Conn. Gen. Stat. Section 38a-495a; Maine 24-A MRSA Section 5001; Mass. Gen. Laws ch. 176K; N.Y. Ins. Law Section 3231(a) and Section 4317.
• California Medigap birthday-rule, Cal. Ins. Code Section 10192.11 (verify current text).