Medigap Underwriting When Leaving Medicare Advantage: What to Expect and How to Pass

Why Underwriting Is the Make-or-Break Step

Switching from Medicare Advantage back to Original Medicare is governed by federal enrollment windows: the Annual Election Period (October 15 to December 7) and the Medicare Advantage Open Enrollment Period (January 1 to March 31). Anyone enrolled in Advantage can use those windows. But the federal calendar only handles half of the transaction.

The other half is convincing a private Medigap insurer to issue you a policy. Unless you qualify for a guaranteed-issue right, the insurer gets to look at your health and decide whether to approve you, charge you more, or decline you outright. That's medical underwriting, and it's where most failed switches fail. Neither AEP nor the MA-OEP, by themselves, creates a federal Medigap guaranteed-issue right in most states.

When You Can Skip Underwriting Entirely

Before we walk through how underwriting works, it's worth knowing when you don't have to deal with it at all. Several paths let you bypass underwriting when leaving Advantage in 2026.

1. Trial Right #1: First-Time Advantage Enrollee at 65

If Medicare Advantage was your first form of Medicare coverage when you turned 65, federal law gives you 12 months to change your mind and buy any Medigap policy sold in your state with guaranteed issue, meaning no health questions and no denials. If you were first eligible for Medicare on or after January 1, 2020, Plans C and F are off the table under MACRA, but Plans A, B, D, G, High-Deductible G, K, L, M, and N remain available. You must apply for Medigap no earlier than 60 days before, and no later than 63 days after, the date your MA coverage ends.

2. Trial Right #2: Dropped Medigap for the First Time

If you previously had a Medigap policy with Original Medicare and dropped it for the first time ever to try Advantage, you get 12 months to return. You have the right to buy back the same Medigap plan from the same carrier if it's still offered, or any Plan A, B, D, G, K, or L sold in your state if it isn't (Plans C and F remain options only for those first eligible for Medicare before January 1, 2020).

3. The 2026 MA Plan Exit Wave

A JAMA study published February 18 found that 10% of Medicare Advantage beneficiaries, approximately 2.9 million, have needed to find other health coverage for 2026 due to MA plans leaving the market. That's a tenfold increase from historical averages: the mean forced disenrollment rate from 2018 to 2024 was 1%, then rose to 6.9% in 2025 and reached 10% for 2026 coverage. KFF's analysis, using a slightly different methodology, puts the number of MA-PD enrollees in terminated plans at about 2.6 million (roughly 13% of the individual MA-PD market). Either way, more people than in any prior year have a federal guaranteed-issue right to buy specific Medigap plans (A, B, D, G, K, or L, plus C and F for pre-2020 eligibles) without medical underwriting, as long as they switch back to Original Medicare. The application window runs from 60 days before your MA coverage ends through 63 days after.

4. Year-Round and Seasonal Guaranteed-Issue States

Connecticut and New York offer the strongest year-round Medigap protections in the country. Insurers in these two states must accept applications from beneficiaries age 65 and older any time during the year without medical underwriting. Massachusetts requires an annual guaranteed-issue open enrollment period (traditionally February through March), and many Massachusetts insurers voluntarily maintain continuous open enrollment. Maine offers a narrower annual guaranteed-issue window (a one-month period chosen by each insurer, primarily for Plan A). Washington allows current Medigap holders to switch to another plan of equal or lesser value without underwriting at any time. Minnesota also added a new annual guaranteed-issue period for enrollees ages 65 to 70 that takes effect August 1, 2026, first usable during the fall Annual Enrollment Period. Maryland recently added new guaranteed-issue windows through HB 275 / SB 134, letting eligible beneficiaries enroll in certain Medigap policies without health questions.

5. Birthday Rule and Other State Windows

The birthday-rule map keeps expanding. As of mid-2026, the 15 states with an active Medigap birthday rule are California, Delaware, Idaho, Illinois, Indiana, Kentucky, Louisiana, Maryland, Nevada, Oklahoma, Oregon, Utah, Virginia, West Virginia, and Wyoming. Delaware's and Indiana's birthday rules took effect January 1, 2026, and West Virginia's took effect for policies effective or renewed starting June 1, 2026. New Mexico's birthday rule was enacted in 2026 but does not begin until January 2027. Window length varies from 30 to 63 days, and most of these protections apply only to existing Medigap holders, not to people switching directly from Advantage. Check your state's rules carefully, and learn more about the Medigap birthday rule states before applying.

For everyone else, the underwriting process described below is what stands between you and a Medigap policy.

What Medigap Underwriting Actually Looks Like

Medicare doesn't standardize underwriting questions, so each carrier writes its own application. That said, most carriers follow the same three-part structure: a knock-out section, a recent-events section with look-back periods, and a chronic conditions and lifestyle section. You can preview the questions by reviewing this Medicare Supplement underwriting guide before applying.

Part 1: Knock-Out Questions (Automatic Decline)

If you answer "yes" to any of these, most carriers will stop reading and deny the application:

• HIV or AIDS
• Alzheimer's, dementia, or other significant cognitive impairment
• ALS, advanced Parkinson's disease, or progressive multiple sclerosis
• Currently on kidney dialysis or scheduled to start
• Currently using supplemental oxygen at home
• Metastatic cancer, leukemia, lymphoma, or active cancer treatment
• Organ transplant pending or recent
• Currently living in a nursing home or skilled nursing facility
• Wheelchair-bound or bedridden from a non-temporary cause
• Needing assistance with two or more activities of daily living (bathing, dressing, eating, transferring)

Part 2: Recent Events With Look-Back Periods

The middle section asks about diagnoses, treatments, surgeries, and hospitalizations within specific timeframes. Look-back periods vary by carrier, but most cluster around 2, 3, and 5 years.

A "yes" here doesn't guarantee a decline, but it usually triggers deeper review and often a rate-up or denial.

Part 3: Chronic Conditions, Medications, and Lifestyle

The final section looks at how well-controlled your existing conditions are and what medications you take. Carriers pull prescription history from a national database, so undisclosed medications will be discovered.

• Diabetes: insulin use (especially over 50 units/day or 3+ medications), A1C control, complications
• Hypertension and cholesterol: recent medication changes or hospitalizations
• Mental health: hospitalizations for depression, bipolar, or schizophrenia
• Substance use: treatment history, current tobacco use
• Build chart: height and weight outside the carrier's normal BMI range (often capped near BMI 40-41)
• Opioids or pain-management clinic involvement

How Carriers Make the Final Decision

After you submit the application, the underwriting team typically does three things:

1. Cross-checks medications against your stated conditions. A drug for heart failure tells them you have heart failure even if you didn't mention it.
2. Runs an MIB (Medical Information Bureau) report and prescription history pull. This shows other insurance applications and pharmacy claims going back several years.
3. Orders a telephone interview or, occasionally, a paramedical exam for borderline cases.

You'll then receive one of four outcomes: standard approval, preferred (best rate) approval, rated approval (higher premium), or decline. Some carriers also impose a pre-existing condition waiting period of up to 6 months for conditions treated in the 6 months before the policy effective date, but only if you didn't have continuous creditable coverage beforehand.

Practical Ways to Improve Your Approval Odds

If you don't qualify for a trial right, plan-exit GI, or a state protection but want to switch anyway, these tactics can meaningfully improve your chances.

Time Your Application During Stable Health

Apply during a period of at least 12 months without hospitalizations, ER visits, medication changes, or new diagnoses. The longer your records show stability, the better.

Get a Soft Pre-Qualification First

Independent Medigap brokers can submit your health profile to multiple carriers informally before any hard application. This shows which insurers are most likely to approve you and avoids a paper trail of declines that future applications will see. You can also ask the broker to walk you through a Medicare Supplement quote on a pre-qualified basis.

Compare Carrier Underwriting Niches

Carriers specialize in different risk profiles. Some are friendlier to diabetics, others to people with prior cancer in remission, others to higher BMI. The same person can be declined by one company and approved at preferred rates by another. Working with a broker who shops at least three of the best Medicare Supplement plans is the single best tactic. Reviewing the best Medicare Supplement insurance companies side by side helps you spot which carrier's underwriting style fits your profile.

Disclose Everything Accurately

Lying on a Medigap application is a quick way to have a claim denied or the policy rescinded within the two-year contestability period. Prescription history checks will catch undisclosed medications, and medical records can be pulled.

Choose the Right Plan Letter

Some carriers underwrite Plan N more leniently than Plan G because Plan N has slightly less rich benefits. It leaves the 2026 Part B deductible of $283 (up $26 from $257 in 2025) and small office and ER copays to the enrollee. If you're a borderline applicant, asking for Plan N can sometimes get you approved when Plan G would be declined. High-Deductible Plan G, with its CMS-confirmed 2026 annual deductible of $2,950 (up from $2,870 in 2025), is another fallback with looser scrutiny at some carriers. See the full Medigap plans comparison chart for a benefit-by-benefit look at each plan letter.

What to Do If You're Declined

A decline isn't the end of the road, but it changes your timing.

1. Stay enrolled in Advantage. Your Advantage plan remains in effect, so you have no coverage gap if Medigap is declined.
2. Re-shop with other carriers. Each insurer underwrites independently. A decline from one company doesn't mean others will follow.
3. Consider Plan N instead of Plan G with the same carrier or a different one.
4. Wait for a guaranteed-issue trigger. Plan exits, service area changes, or moving across state lines can create a GI right. With 2026's wave of MA terminations affecting roughly 1 in 10 enrollees, more people will qualify than in any prior year.
5. Review your state's options. State Health Insurance Assistance Programs (SHIPs) sometimes know about niche state programs that aren't widely advertised. The Medicare Supplement plans by state guide can also help, and the Medicare Supplement Open Enrollment rules outline additional state-specific protections.

For a broader walkthrough of timing the whole transition, see our step-by-step Medicare Advantage to Medigap switching guide. For a head-to-head look at the two coverage models, our Medigap vs Medicare Advantage comparison lays out the trade-offs.

Frequently Asked Questions

Do I have to answer medical questions to leave Medicare Advantage for Medigap?

Only if you don't have a guaranteed-issue right. Federal trial rights for first-time Advantage enrollees, year-round guaranteed issue in Connecticut and New York, and federal GI triggers like the 2026 plan exits all let you skip underwriting. Outside those situations, most states allow insurers to ask detailed health questions and decide whether to approve you.

What's the most common reason Medigap underwriting denies an application?

Recent cancer treatment, heart attacks within the last two years, current oxygen use, insulin-dependent diabetes with complications, and active chemotherapy or radiation are the most common automatic declines. Carriers also decline for current nursing-home residence, dialysis, dementia, and needing help with two or more activities of daily living. Less severe conditions usually result in a rate-up or pre-existing condition waiting period rather than a flat denial.

Will carriers check my prescription records when I apply?

Yes. Almost all Medigap underwriters pull a prescription history report from a national database that shows medications filled over the past several years. The drugs you've taken tell the underwriter what conditions you have, so undisclosed conditions almost always come to light. Always disclose accurately on the application.

How long does Medigap underwriting take in 2026?

Most carriers issue a decision within 5 to 14 business days for clean applications. Borderline cases that require a telephone interview, additional medical records, or a paramedical exam can take 3 to 6 weeks. Apply early in your AEP or trial-right window so you have buffer time for follow-up questions.

Can I be denied even if I've been healthy on Medicare Advantage for years?

Yes, because underwriting looks at your entire medical history, not just your time on Advantage. A heart attack five years ago, a recent cancer scare, or a planned surgery can trigger a decline regardless of how stable you've been recently. Get a soft pre-qualification before submitting a formal application to gauge your real approval odds.