Hawaii Medicare Supplement: Any-Age Window and Guaranteed Issue (2026)

In Hawaii, a person under 65 who has just enrolled in Medicare Part B gets the same six-month Medigap open enrollment window as a 65-year-old.1 Hawaii Medicare Supplement rules start that window with the first month of Part B enrollment and apply it without regard to age.1 Federal law, by contrast, starts the Medigap Open Enrollment Period only in the first month a person is both 65 or older and enrolled in Part B.2 During the Hawaii window, Hawaii Administrative Rules (HAR) §16-12-6.2 bars an issuer from denying, conditioning or pricing a Medigap policy because of an applicant's health status, claims experience, receipt of health care or medical condition.1 After the window closes, HAR §16-12-6.3 gives people in seven specified situations, such as losing employer or Medicare Advantage coverage, a guaranteed-issue right whose deadline is 63 days after a stated event, and the application has to include evidence of the termination or disenrollment date.1

In This Guide

• Does Hawaii's Medigap Window Apply If You're Under 65?
• When Does the Hawaii Medicare Supplement Window Start and End?
• Will a Pre-Existing Condition Be Covered Right Away?
• When Must a Hawaii Insurer Sell You a Medigap Policy Later?
• Can You Switch Medigap Policies Without a New Waiting Period?
• What Protections Come After You Buy?
• Which Plans Can You Buy, and Is Medigap or Medicare Advantage the Better Fit?
• Hawaii Medigap Protections at a Glance
• Where Can You Get Help With a Hawaii Medicare Supplement Question?
• Frequently Asked Questions
• Learn More

Does Hawaii's Medigap Window Apply If You're Under 65?

Yes. Hawaii's open enrollment rule is tied to Part B enrollment, and HAR §16-12-6.2(a) says each Medicare Supplement policy and certificate an issuer currently has available "shall be made available to all applicants who qualify under this subsection without regard to age."1 A 58-year-old in Hilo who has Medicare because of a disability and has just started Part B therefore qualifies for the same six-month Hawaii window as a 65-year-old in Honolulu who has just started Part B.

Federal law draws the line differently. Under Section 1882 of the Social Security Act, subsection (s)(2)(A), the federal six-month Medigap Open Enrollment Period begins with the first month a person is both 65 or older and enrolled in Part B.2 Medicare.gov says federal law generally doesn't require insurance companies to sell Medigap policies to people under 65, although insurers in some states do offer them.2 Hawaii's rule text is one of those state-level additions, and Medicare's guide Choosing a Medigap Policy notes that some states have additional open enrollment periods, including those for people under 65.1

Read the pricing protection closely. The HAR §16-12-6.2(a) pricing bar names four grounds: health status, claims experience, receipt of health care and medical condition.1 Age is not one of the grounds HAR §16-12-6.2(a) lists, so an applicant under 65 should compare quotes rather than assume a Hawaii insurer will charge the same premium it charges a 65-year-old. Brevy's guide to how Medigap premiums are priced explains the rating methods insurers use.

When Does the Hawaii Medicare Supplement Window Start and End?

The Hawaii window is the six-month period beginning with the first day of the first month in which a person is enrolled for benefits under Medicare Part B.1 For someone whose Part B starts on March 1, for example, the six months run through the end of August, and an application submitted in that stretch gets the HAR §16-12-6.2 protections.

The federal Medigap Open Enrollment Period is a one-time window that doesn't repeat every year, according to Medicare.gov.2 Medicare's guide Choosing a Medigap Policy also states that if you already have Medicare Part B, you'll still get a Medigap Open Enrollment Period when you turn 65, so a Hawaii resident who first bought Medigap under 65 should mark that birthday on the calendar.1 That second window is Medicare's statement, not a provision of the HAR text quoted here. See Brevy's guide to the Medigap open enrollment period for how the federal window works in every state.

Outside a protected window, Medicare.gov warns that an insurance company is allowed to deny a Medigap policy to an applicant who doesn't meet its medical underwriting requirements.2

Will a Pre-Existing Condition Be Covered Right Away?

Whether a Hawaii Medigap policy covers a pre-existing condition from day one depends on how much creditable coverage the applicant had before applying. HAR §16-12-6.2(b) sets two rules for applicants who buy during the six-month window:1

• Six months or more of creditable coverage: If a Hawaii applicant has had a continuous period of creditable coverage of at least six months as of the application date, the issuer shall not exclude benefits based on a pre-existing condition.
• Less than six months: If the continuous creditable coverage is shorter than six months, the Hawaii issuer must reduce any pre-existing condition exclusion period by the total creditable coverage the applicant had as of the enrollment date.

Except as subsection (b), HAR §16-12-6.3 (guaranteed issue) and HAR §16-12-12.8 (replacement) provide, HAR §16-12-6.2(c) does not prevent a Hawaii Medigap policy from excluding benefits during its first six months for a pre-existing condition that was treated or diagnosed during the six months before the coverage took effect.1 Both of those later rules are covered below. Brevy's explainer on Medigap and pre-existing conditions walks through the waiting-period mechanics in more detail.

When Must a Hawaii Insurer Sell You a Medigap Policy Later?

Hawaii's guaranteed-issue rule, HAR §16-12-6.3, applies to seven groups of eligible persons. For a person in one of these groups who applies during the guaranteed-issue period and submits the required evidence, a Hawaii issuer may not deny or condition certain Medigap policies it offers to new enrollees, may not price the policy on health status, claims experience, receipt of health care or medical condition, and may not impose a pre-existing condition exclusion.1 Which lettered plans count as those policies depends on the situation, so check Brevy's guide to Medigap guaranteed issue rights and confirm with the insurer before you apply.

The seven HAR §16-12-6.3(b) groups, in plain language:1

1. Employer plan ends: You're enrolled under an employee welfare benefit plan that supplements Medicare, and the plan terminates or stops providing all of those supplemental benefits to you.
2. Medicare Advantage plan ends or you must leave it: Your Medicare Advantage plan's certification is terminated, the plan stops serving your area, you move or have another specified change that ends your eligibility, the plan terminates for everyone in your area, the organization substantially violated a material contract provision or materially misrepresented the plan in marketing, or you meet other exceptional conditions the Secretary may provide under federal Medicare law. A person 65 or older in a Program of All-Inclusive Care for the Elderly (PACE) in similar circumstances is included. Under the change-in-circumstances clause, an enrollment ended because you didn't pay premiums on time or engaged in disruptive behavior does not count.
3. Other Medicare plan ends: Your enrollment in a Medicare cost plan, a health care prepayment plan, a similar demonstration organization (for periods before April 1, 1999) or a Medicare SELECT policy ends under circumstances that would permit leaving a Medicare Advantage plan.
4. Your Medigap policy ends through no fault of yours: The issuer becomes insolvent or goes bankrupt, the coverage is otherwise involuntarily terminated, or the issuer substantially violated the policy or materially misrepresented it in marketing.
5. You tried Medicare Advantage for the first time: You dropped a Medigap policy to join a Medicare Advantage plan, cost plan, PACE provider or Medicare SELECT policy for the first time, and you leave it within the first twelve months.
6. You chose Medicare Advantage at 65: When you first enrolled in Medicare Part A at 65 or older, you joined a Medicare Advantage plan or a PACE provider, and you disenroll no later than twelve months after the enrollment took effect.
7. You moved your drug coverage to Part D: You enrolled in a Medicare Part D plan during your initial enrollment period while holding a Medigap policy that covered outpatient prescription drugs, and you terminated that Medigap policy.

How long does a Hawaii guaranteed-issue period last?

Every guaranteed-issue period in HAR §16-12-6.3(c) ends 63 days after a stated event, but the start and end points differ by group:1

• Employer plan ending: The Hawaii period begins on the later of the date you receive notice that all supplemental benefits are ending (or, without a notice, notice that a claim was denied because of it) or the date the coverage ends, and it runs 63 days from there.
• Involuntary termination in groups 2, 3, 5 or 6 above: The Hawaii period begins when you receive the termination notice and ends 63 days after the coverage terminates.
• Voluntary disenrollment in groups 2, 5 or 6, or in group 4 when the issuer violated or misrepresented the policy: The Hawaii period opens 60 days before the disenrollment takes effect and closes 63 days after that effective date, so you can apply ahead of time.
• Medigap insolvency or other involuntary termination: The Hawaii period ends 63 days after the coverage is terminated.
• Part D switch: The Hawaii period ends 63 days after your Medicare Part D coverage takes effect.
• Any other eligible person: The Hawaii period begins on the effective date of disenrollment and ends 63 days after it.

What proof should you keep?

HAR §16-12-6.3(a) defines eligible persons as those who submit evidence of the date of termination, disenrollment or Medicare Part D enrollment with the Medigap application.1 Medicare's guide Choosing a Medigap Policy advises keeping copies of letters, notices, emails or claim denials with your name on them as proof that coverage was terminated, along with the postmarked envelope as proof of when the papers were mailed.1 A Honolulu retiree whose employer plan is ending should keep the termination letter and its envelope together, because some or all of those papers may need to go in with the Medigap application.

Can You Switch Medigap Policies Without a New Waiting Period?

Hawaii's replacement rule, HAR §16-12-12.8, protects the time you have already spent under a Medigap policy. When one Medigap policy replaces another in Hawaii, the replacing issuer must waive any pre-existing condition periods, waiting periods, elimination periods and probationary periods for similar benefits, to the extent that time was spent under the original policy.1 If the replaced Hawaii policy had been in effect for at least six months, the replacing policy may not impose any of those time periods for benefits similar to those in the original policy.1 Social Security Act §1882(s)(2)(C) sets the same six-month federal rule for replacement policies.3

The replacement rule protects time credit, not the right to buy. Medicare.gov says that in most cases you won't be able to switch your Medigap policy outside your six-month Medigap Open Enrollment Period except in specific situations when you have a guaranteed issue right, and that switching outside that period may mean paying more and answering medical questions.3 Medicare.gov also warns that if you drop a Medigap policy, you might not be able to get it or any policy back later, so keep the old policy until the new one is approved.3

When you do switch, Medicare's guide says you have 30 days to decide whether to keep the new Medigap policy, and that you'll pay both premiums for the month you have both.1

What Protections Come After You Buy?

Hawaii statute gives every Medicare Supplement buyer a 30-day look. Hawaii Revised Statutes (HRS) §431:10A-308 requires a notice on the first page of each Medigap policy, or attached to it, stating that the buyer may return the policy within 30 days of delivery and have the premium refunded if not satisfied for any reason.1 HRS §431:10A-308 also requires the issuer to pay any such refund directly to the applicant in a timely manner.1 Federal law adds a parallel floor: Social Security Act §1882(c)(4) lets a Medigap policy be returned for a full refund of premiums paid during a period of not less than 30 days after it is issued.3

A Hawaii Medigap policy sold under the state's 2010 standardized plan benefit standards is guaranteed renewable. HAR §16-12-5.6, the benefit standard for those 2010 standardized plans, says an issuer may not cancel or non-renew a Medigap policy solely because of the policyholder's health status, or for any reason other than nonpayment of premium or material misrepresentation.1 Medicare's guide separately states that any new Medigap policy issued since 1992 is guaranteed renewable even if you have health problems.1

Which Plans Can You Buy, and Is Medigap or Medicare Advantage the Better Fit?

Medigap policies are standardized by plan letter. Medicare's 2026 guide Choosing a Medigap Policy charts Plans A, B, C, D, F, G, K, L, M and N, and states that every insurance company that sells Medigap policies must offer at least Plan A.1 Plans E, H, I and J are no longer sold, though someone who already has one can generally keep it.1

Plans C and F are closed to people new to Medicare. Medigap plans sold to people new to Medicare on or after January 1, 2020 aren't allowed to cover the Part B deductible, so Plans C and F are no longer available to them, and they have the right to buy Plans D and G instead.1 Under Medicare's definition, a person is new to Medicare for this rule if they turned 65 on or after January 1, 2020 and got Part A on or after that date; someone eligible before 2020 who hasn't yet enrolled may still be able to buy Plan C or F.1 For a side-by-side of the two most-compared letters, see Brevy's Plan G vs Plan N guide.

Medigap works only with Original Medicare. Medicare's booklet on Medicare Advantage says you can't use Medigap to pay Medicare Advantage copayments, coinsurance, deductibles or premiums, and that it's illegal for anyone to sell you a Medigap policy while you're in a Medicare Advantage plan unless you're switching back to Original Medicare.4 The same booklet warns that in most cases, if you drop a Medigap policy to join a Medicare Advantage plan, you may not be able to get the same policy back.4 The federal "trial right" softens that risk: someone who joins a Medicare Advantage plan for the first time can buy a Medigap policy and a separate drug plan if they return to Original Medicare within 12 months of joining.4 Brevy's guide to switching between Medicare Advantage and Original Medicare covers the trial right step by step.

Hawaii Medigap Protections at a Glance

The table summarizes the Hawaii Medigap rules in HAR Chapter 16-12 and HRS §431:10A-308 described above.1

Where Can You Get Help With a Hawaii Medicare Supplement Question?

The DCCA Insurance Division's Medigap page describes Medigap as extra insurance you buy from a private company to help pay your share of Original Medicare costs, and it links a list of Medicare Supplement (Medigap) companies dated January 2026.1

• A problem with an insurer: Hawaii's Insurance Division encourages consumers to speak with an Insurance Division investigator before filing a complaint, at 1-844-808-DCCA (3222), 7:45 a.m. to 4:30 p.m. Hawaii Standard Time, Monday to Friday except state holidays.1 The Division's complaint page also links an online complaint form.
• Checking a guaranteed-issue right: Medicare's guide advises calling your State Health Insurance Assistance Program (SHIP) to confirm that you qualify for a guaranteed issue right, and says shiphelp.org gives the number for your local SHIP, such as Hawaii SHIP.1
• A denial: Medicare's guide says to call your State Insurance Department if you're denied Medigap coverage in a guaranteed-issue situation; in Hawaii, the Insurance Division's investigator line above is the place to start.1
• Federal Medicare questions: 1-800-MEDICARE (1-800-633-4227) connects you with a real person 24 hours a day, 7 days a week, except some federal holidays; TTY users call 1-877-486-2048.5

Learn More

Find personalized help choosing and timing a Medicare Supplement policy in Hawaii at brevy.com.

The information on Brevy.com is for educational purposes only and is not a substitute for professional legal, financial, or medical advice. Rules vary by state and program and change frequently. Always verify with the relevant agency or a qualified professional. Brevy is not a law firm, financial advisor, or healthcare provider.