Medigap Underwriting and Guaranteed-Issue Rights: A Practical Guide for Agents

A healthy client may still face carrier underwriting. A client with significant health conditions may qualify for guaranteed issue. A third client may have a state birthday right - but only for the same plan, equal-or-lesser benefits, or a policy from the current carrier.

Classifying the case before quoting helps agents avoid preventable declines, missed deadlines, inappropriate replacements, and coverage gaps. If the appointment will also include plan-specific Medicare Advantage or Part D discussion, first check whether an SOA is required for the Medigap appointment.

The basic Medigap decision tree

Most Medigap applications fit one of five paths:

1. Initial Medigap Open Enrollment Period
2. Federal guaranteed-issue right
3. Federal first-year trial right
4. State-created enrollment protection, such as a birthday rule
5. Carrier medical underwriting

The federal Medigap framework is set out in 42 U.S.C. Section 1395ss. For day-to-day casework, Medicare’s current buying guidance explains that the beneficiary’s one-time, six-month Medigap Open Enrollment Period starts in the first month the person is both 65 or older and enrolled in Medicare Part B. Outside that period, a beneficiary generally has no federal right to change Medigap policies unless a specified guaranteed-issue or trial-right situation applies. States can provide additional protections. The official 2026 Medicare Medigap guide is the best starting point for the full federal analysis.

What does guaranteed issue mean for Medigap?

A federal guaranteed-issue right is a right to purchase certain Medigap policies in specified situations outside the initial Medigap Open Enrollment Period. Medicare’s guaranteed-issue guidance explains both the protected situations and why the applicant should preserve proof of the qualifying event.

When a valid right applies, the insurance company generally must:

• Sell the applicant an eligible Medigap policy;
• Cover the applicant’s preexisting health conditions; and
• Refrain from charging more because of past or present health problems.

Guaranteed issue does not necessarily mean every plan is protected, every carrier sells every plan, or the application can be submitted at any time. It also does not eliminate proof requirements, replacement notices, effective-date coordination, or the non-health portions of the carrier application.

An application can be guaranteed issue and still require the agent to prove the qualifying event, calculate the correct deadline, select an eligible plan, and complete the replacement paperwork.

Initial Medigap Open Enrollment is not an annual event

The federal Medigap Open Enrollment Period is a one-time six-month period. During it, the applicant may buy any Medigap policy the carrier offers in the state, and the carrier cannot use medical underwriting to deny the application or charge more because of health. Medicare’s open-enrollment explanation also makes clear that this federal period does not repeat each year.

This is different from Medicare’s annual enrollment periods for Medicare Advantage and Part D. AEP does not, by itself, create a federal right to move from one Medigap policy to another without underwriting. A separate Medigap open-enrollment, guaranteed-issue, trial-right, state-law, or carrier-underwriting path must apply.

Do not treat open enrollment and guaranteed issue as identical

Initial Medigap Open Enrollment prevents health-based denial and pricing, but the official Medigap guide’s discussion of preexisting conditions explains that a waiting period may still be allowed in some circumstances. Prior creditable coverage can reduce or eliminate that waiting period.

By contrast, Medicare describes federal guaranteed-issue protections as requiring the carrier to cover all preexisting health conditions without a preexisting-condition waiting period. The practical lesson is simple: document the exact right instead of writing only “GI” or “open enrollment” in the file.

Common federal Medigap guaranteed-issue situations

The Medicare guaranteed-issue table lists the most common federal situations, while Medicare’s online timing guide is useful for checking when an application window begins and ends. This field summary is designed to help agents identify which row they need to verify.

Plans C and F require a separate eligibility check

Medicare’s plan-eligibility guidance explains that Plans C and F generally are unavailable to people who became newly eligible for Medicare on or after January 1, 2020. For those beneficiaries, Plans D and G substitute for C and F in the applicable federal provisions.

This is why an agent should not say, “You have guaranteed issue, so you can choose any plan.” In many common federal situations, Plan N is not protected. It may still be available during initial Medigap Open Enrollment, under the first type of trial right, under state law, or after successful carrier underwriting.

The 63-day rule does not always start on the same date

“Sixty-three days” is one of the most repeated Medigap rules and one of the easiest to calculate incorrectly. Depending on the qualifying event, the period may run from:

• The date coverage terminates;
• The date shown on a termination notice;
• The date the client receives notice;
• The date of a claim denial;
• The effective date of Medicare Advantage disenrollment; or
• The latest of several possible dates.

For secondary employer or retiree coverage, for example, Medicare’s event-specific guaranteed-issue guidance measures the period from the latest of the coverage-ending date, the date on the notice, or the claim-denial date if that is how the client first learns that coverage ended.

Evidence agents should obtain

Ask the client to retain:

• Termination and nonrenewal letters;
• Emails about loss of coverage;
• Claim denials;
• Medicare Advantage disenrollment confirmation;
• The postmarked envelope in which a notice arrived; and
• Documents showing the actual coverage-ending date.

Medicare specifically tells beneficiaries to keep this evidence because it may be needed with the Medigap application. More than one guaranteed-issue situation can sometimes apply; when that happens, the beneficiary may use the right that works best. The agent file should identify the qualifying event, evidence, and exact date used to calculate the deadline.

The two federal trial rights are different

Agents often refer to one general “12-month trial right,” but federal guidance describes two materially different situations.

Trial right 1: MA or PACE when first eligible at age 65

Under Medicare’s first federal trial-right guidance, this right can apply when the client joined Medicare Advantage or PACE when first eligible for Medicare Part A at age 65, has been enrolled for less than one year, and wants to return to Original Medicare. The protected choice is broad: any Medigap policy sold by an insurance company in the state.

Example: Maria enrolled in Medicare Advantage when she first became eligible at 65. Nine months later, provider access and travel needs point her toward Original Medicare with Medigap. The agent should confirm the initial enrollment facts, coordinate a valid return to Original Medicare, submit within the protected period, and request a Medigap effective date after MA ends. Medigap cannot begin while Maria remains in Medicare Advantage.

Trial right 2: the client dropped Medigap to try MA or SELECT

Medicare’s second federal trial-right guidance covers a different situation: the client had Medigap, dropped it to join Medicare Advantage or switch to Medicare SELECT for the first time, has been there less than a year, and wants to return.

The first protected option is the former Medigap policy from the former carrier if it is still sold. If that policy is unavailable, the client generally may purchase Plans A, B, C, D, F, or G, as applicable.

Example: David had Plan G, dropped it to try Medicare Advantage for the first time, and wants to return after ten months. The first question is not which Plan G carrier is cheapest. It is whether David’s former carrier still sells his former policy.

When carrier medical underwriting applies

If the client is outside initial Medigap Open Enrollment and has no federal right or applicable state protection, the proposed carrier may medically underwrite the application. Medicare’s buying guidance cautions that outside open enrollment, a carrier may deny coverage or charge more based on health; the exact application process remains subject to state law and the carrier’s approved standards.

Carrier standards are not uniform. One carrier’s treatment of a diagnosis, medication, hospitalization, mobility aid, or pending procedure may differ from another’s, and guides can change.

A practical underwriting prescreen

Before recommending a replacement, gather enough information to use the proposed carrier’s current application and underwriting guide. Common areas include:

• Recent diagnoses, treatment, or medical advice;
• Pending tests, referrals, surgery, or procedures;
• Hospital, rehabilitation, skilled-nursing, or home-health use;
• Current prescriptions and recent medication changes;
• Cancer, cardiac, pulmonary, renal, neurological, or vascular history;
• Mobility devices or assistance with activities of daily living;
• Height, weight, and tobacco use; and
• Recent insurance declines.

These are common categories, not a universal decline list.

Three rules help keep prescreening honest:

1. Read the question actually on the application. Do not substitute an old question or an agent’s memory of the guide.
2. Do not call a prescreen an approval. Final approval may depend on the complete application, prescription history, records, or a verification interview.
3. Require complete answers. Medicare warns that a standardized Medigap policy can be terminated if the insured was not truthful on the application.

Example: Robert has Plan G and wants a lower premium. He is seven years past his initial open enrollment and has no coverage-loss event, trial right, or state opportunity. This is an underwritten replacement even if Robert considers himself healthy. Keep his current policy in force until the replacement is issued and accepted.

Guaranteed issue and replacement are separate questions

Answer three separate questions on every proposed switch:

1. Is this transaction a replacement?
2. Does the applicant have a guaranteed-issue or other protected enrollment right?
3. Does that right permit this plan from this carrier?

A guaranteed-issue application can still be a replacement. A replacement can still be medically underwritten. A birthday rule may protect a replacement only when the proposed plan and carrier satisfy that state’s exact restrictions.

A practical Medigap replacement workflow

Step 1: document the existing coverage

Record the current carrier, plan letter and variation, original effective date, premium, state, rating method, discounts, high-deductible status, deductible accumulation, and innovative benefits. Review the policy, ID card, premium notice, or policy schedule rather than relying only on memory.

Step 2: classify the enrollment right

Write down whether the case uses initial open enrollment, a federal guaranteed-issue event, trial right 1, trial right 2, a state protection, or medical underwriting. Record the application deadline.

Step 3: determine which plans and carriers are protected

Ask whether the right permits any plan or only specified plans; whether C or F is available; whether the switch is same-letter or equal-or-lesser; whether the client must remain with the same issuer; and whether the state publishes an equivalency matrix.

“Equal or lesser” is a legal benefit comparison. It is not an alphabetical ranking of plan letters.

Step 4: compare more than the first-month premium

Compare standardized benefits, current and proposed premiums, discounts and their duration, rating method, rate history when available, effective dates, deductible accumulation, innovative benefits, billing, and the cost of overlapping coverage. Medicare notes that the same lettered policy can carry a different premium from one company to another, even though its standardized basic benefits are the same.

Step 5: complete the replacement documents

The NAIC model regulation provides a commonly used framework: identify the replacement, furnish the notice, obtain signatures, give a copy to the applicant, and retain a copy. Actual requirements depend on state law and the carrier’s approved forms.

Step 6: wait for issuance and confirm the effective date

An application receipt, preliminary indication, or premium draft is not an issued policy. Confirm approval, rate, effective date, termination timing for prior coverage, accepted first premium, and delivery of policy materials.

Step 7: use the 30-day free-look period correctly

Medicare advises clients not to cancel the existing Medigap policy until they have decided to keep the new one. The 30-day free-look period starts when the new policy is received. The client may need to pay both premiums during the overlap.

When a current policy has been held for less than six months, the new policy may impose a remaining preexisting-condition waiting period, reduced by qualifying prior coverage. A waiting period may also apply to a new benefit absent from the prior policy. Verify this separately from the underwriting decision.

State Medigap birthday rules for agents

State laws can expand a client’s ability to change Medigap coverage without health underwriting. They are not uniform. Some allow any carrier, while others restrict the client to the same issuer or an affiliate. Some allow equal-or-lesser benefits; others require the same plan or same benefits.

The following summary is current as of July 13, 2026. The state name in every card links directly to the applicable department of insurance, legislature, regulation, bulletin, or official state guidance. Verify that authority and the proposed carrier’s current instructions before promising that a particular application is protected.

New Mexico begins in 2027

New Mexico SB 21 creates an annual protection effective January 1, 2027. The window begins on the first day of the policyholder’s birthday month and remains open for at least 60 days. It permits an equal-or-lesser-value policy offered in the state without health-based denial or health-based price discrimination.

Birthday rules are not interchangeable

• Under Virginia’s official guidance, a Plan G client can use the birthday rule for another Plan G, but not Plan N.
• Indiana’s SHIP guidance allows a client to move from Plan G to Plan G through another carrier, but not Plan G to Plan N.
• Under Illinois’s administrative rule, a client who is 77 does not meet the birthday enrollment period’s age limit.
• Utah law requires the client to remain with the same issuer.
• Louisiana law limits the protected change to the same issuer or an affiliate.
• Oregon’s official comparison matrix and Idaho’s state guidance provide broader carrier access, but the proposed plan still must satisfy the state’s comparison rule.

Practical Medigap sales scenarios

California client with serious health conditions

Angela has California Plan G and recently underwent cardiac treatment. She may have difficulty in ordinary underwriting, but she is within the period described in the California Department of Insurance’s birthday-rule guidance. Her medical history does not eliminate that protection. The agent should verify equal-or-lesser benefits, carrier instructions, the birthday window, and replacement forms.

Virginia Plan G client wants Plan N

James is inside the Virginia State Corporation Commission’s 60-day birthday period and wants Plan N for the lower premium. Virginia protects a move to the same benefits, such as Plan G to Plan G. Plan G to Plan N may require underwriting unless James has another enrollment right. A lower premium does not make Plan N “the same” under the Virginia rule.

Employer retiree coverage is ending

Michael has Original Medicare and retiree coverage that pays after Medicare. The employer is ending that coverage. Under Medicare’s coverage-loss guidance, he may have a federal guaranteed-issue right. Obtain the termination notice, identify all possible trigger dates, and calculate the deadline from the latest applicable federal date. Do not delay solely because coverage has not ended; application and effective dates may be coordinated in advance.

MA enrollment at age 65

Susan joined Medicare Advantage when first eligible at 65. Eleven months later, she wants Original Medicare and Medigap. Under Medicare’s trial-right explanation, she may qualify for trial right 1, which can permit any Medigap policy sold in the state. The agent still must coordinate MA disenrollment, Original Medicare, the Medigap deadline, and effective date.

High-deductible replacement in Oregon

Edward has a high-deductible policy and has already accumulated substantial covered expenses toward the annual deductible. He qualifies to change carriers during Oregon’s birthday period. The agent should not compare premiums alone: Oregon’s official Medigap comparison matrix warns that a midyear high-deductible switch can restart the deductible under the new contract.

Common Medigap errors agents should avoid

• Treating AEP as Medigap open enrollment. Medicare’s policy-change guidance does not make AEP a federal right to replace Medigap without underwriting.
• Assuming guaranteed issue means any plan. The federal guaranteed-issue table protects Plans A, B, C, D, F, and G as applicable in many common situations, not Plan N.
• Combining the two trial rights. Medicare’s trial-right explanation shows that the protected options are different.
• Calculating every deadline from termination. Medicare’s event-specific timing guidance shows that notice, claim-denial, or disenrollment dates may control.
• Canceling the existing policy before issuance. Medicare says to keep the old policy until the client decides to keep the new one.
• Assuming every birthday rule allows any carrier. Several states impose issuer or affiliate restrictions.
• Ranking plan letters alphabetically. Equal-or-lesser benefits require the state’s legal standard or matrix.
• Ignoring deductible and discount resets. Household discounts, payment discounts, and deductible accumulation can change.
• Discarding event proof. Notices, emails, envelopes, and denials may determine whether the carrier recognizes the right.

Agent file checklist

For a protected or underwritten replacement, the file should ordinarily contain:

• Medicare Part A and Part B effective dates;
• Current Medigap carrier, plan, variation, policy date, and premium;
• The legal or underwriting path used;
• The exact application-window calculation;
• Termination notices and other supporting evidence;
• The applicable state rule or carrier bulletin;
• The current underwriting guide version, when used;
• Required replacement and disclosure forms;
• Carrier approval, rate, and confirmed effective date;
• MA or prior-policy termination confirmation; and
• Documentation of the client’s free-look decision.

Final takeaway for agents

That sequence helps protect clients while reducing avoidable declines, coverage gaps, incorrect plan recommendations, and replacement complaints.

When the same appointment includes specific Medicare Advantage or Part D options, documentation has a second layer: the product discussion needs the right appointment scope. A clean electronic Scope of Appointment workflow lets an agent send a written scope by text or email, track pending and signed status, and store the completed record with the rest of the client file.

Sources

• 42 U.S.C. 1395ss - Medicare supplemental policies: Office of the Law Revision Counsel, U.S. House of Representatives Accessed 2026-07-13.
• Choosing a Medigap Policy: 2026 official guide: Centers for Medicare & Medicaid Services and National Association of Insurance Commissioners Accessed 2026-07-13.
• Get ready to buy a Medigap policy: Medicare.gov Accessed 2026-07-13.
• When can I buy Medigap?: Medicare.gov Accessed 2026-07-13.
• Learn how Medigap works: Medicare.gov Accessed 2026-07-13.
• Can I change my Medigap policy?: Medicare.gov Accessed 2026-07-13.
• NAIC Medicare Supplement Insurance Minimum Standards Model Regulation: National Association of Insurance Commissioners Accessed 2026-07-13.
• California Medigap birthday rule: California Department of Insurance Accessed 2026-07-13.
• Delaware Medicare Supplement birthday rule fact sheet: Delaware Department of Insurance Accessed 2026-07-13.
• Idaho Medicare Supplement law and rule changes: Idaho Department of Insurance Accessed 2026-07-13.
• Illinois Medicare Supplement birthday enrollment rule: Illinois General Assembly Accessed 2026-07-13.
• Indiana Medigap birthday rule: Indiana State Health Insurance Assistance Program Accessed 2026-07-13.
• Kentucky Administrative Regulation 806 KAR 17:570: Kentucky Legislative Research Commission Accessed 2026-07-13.
• Louisiana Revised Statutes 22:1112: Louisiana State Legislature Accessed 2026-07-13.
• Maryland Medicare Supplement FAQs: Maryland Insurance Administration Accessed 2026-07-13.
• Nevada Medicare Supplement birthday rule guidance: Nevada Division of Insurance Accessed 2026-07-13.
• Oklahoma Medicare Supplement open enrollment FAQs: Oklahoma Insurance Department Accessed 2026-07-13.
• Oregon Medigap birthday rule matrix: Oregon Division of Financial Regulation Accessed 2026-07-13.
• Utah Code 31A-22-620: Utah State Legislature Accessed 2026-07-13.
• Virginia Medigap birthday rule: Virginia State Corporation Commission Accessed 2026-07-13.
• West Virginia HB 4869, enrolled: West Virginia Legislature Accessed 2026-07-13.
• Wyoming Medicare Supplement birthday rule update: Wyoming Department of Insurance Accessed 2026-07-13.
• New Mexico SB 21, final version: New Mexico Legislature Accessed 2026-07-13.

Frequently Asked Questions

Can a client change Medigap policies during Medicare AEP?

The client can apply, but AEP by itself does not create a federal right to change Medigap policies without underwriting. The client needs initial Medigap Open Enrollment, a guaranteed-issue or trial right, an applicable state protection, or carrier approval through underwriting.

Can a Medigap carrier ask health questions during guaranteed issue?

The application may contain health, eligibility, and replacement questions. When a valid guaranteed-issue protection applies, the carrier cannot use health answers to deny the protected policy or charge more because of health, but the agent must still prove that the applicant, date, plan, and carrier satisfy the right.

Is Plan N federally guaranteed issue?

Plan N is not in the common federal guaranteed-issue plan list in Medicare's current guide. It may still be available during initial Medigap Open Enrollment, under the first Medicare Advantage trial right, under an applicable state protection, or after medical underwriting.

Can a client move from Plan G to Plan N under a birthday rule?

It depends on the state. Some states protect equal-or-lesser benefits, while others require the same plan or same benefits. Virginia and Indiana, for example, do not protect a Plan G-to-Plan N change under their birthday rules.

How long is a Medigap guaranteed-issue period?

Many federal rights include a period ending 63 days after a specified event, but there is no single starting date for every event. The clock may depend on the coverage-ending date, notice date, claim-denial date, or effective date of disenrollment.

Should the client cancel the old Medigap policy before the new one is approved?

No. The client should generally wait until the replacement has been issued and use the 30-day free-look period to decide whether to retain it. The client may need to pay both premiums during the overlap.

Does a high-deductible Medigap deductible transfer to a new carrier?

Not necessarily. Oregon expressly warns that a midyear switch between high-deductible policies can restart the deductible under the new carrier's contract. Verify the applicable state and carrier treatment before recommending the change.

Does guaranteed issue eliminate replacement paperwork?

No. Guaranteed-issue status affects eligibility, health underwriting, and pricing. It does not necessarily eliminate replacement notices, disclosure forms, proof of the qualifying event, or effective-date coordination.