Medicare in Guam covers hospital and doctor care under the same federal rules that apply on the mainland, but the private plan market that surrounds Medicare almost everywhere else is nearly absent here. There are no Medicare Advantage plans on the island for 2026, only one stand-alone Part D drug plan, and a small pool of Medigap insurers. That shapes almost every coverage decision you’ll make.
What’s Different About Medicare in Guam
Original Medicare — Part A for hospital care and Part B for doctor and outpatient services — is the coverage almost every Guam beneficiary starts and stays with, because it’s the only form of Medicare universally available on the island.
No Medicare Advantage (Part C) plans are sold in Guam for 2026. The bundled private plans that roughly half of mainland beneficiaries use, often with dental, vision, hearing extras and an annual out-of-pocket cap, don’t exist here. The small population and geographic isolation make it unprofitable for insurers to build networks. If you’re moving to Guam from a state where you had a Medicare Advantage plan, you’ll be switched to Original Medicare, and you’ll want to look at a Medigap policy and the island’s one Part D plan.
The practical effect: Guam beneficiaries need to plan coverage more carefully than someone in a mainland city where dozens of private options compete.
Signing Up and Enrollment Deadlines
Eligibility follows the standard federal rules. You qualify at 65 or older, after 24 months of Social Security Disability Insurance benefits, or with End-Stage Renal Disease or ALS.1HHS.gov. Who’s Eligible for Medicare? ALS is the exception to the 24-month wait; Medicare begins the first month you receive disability benefits for ALS.2Social Security Administration. Medicare Information
If you already receive Social Security or Railroad Retirement Board benefits, you’re automatically enrolled in Part A and Part B when you turn 65. Otherwise, sign up during your Initial Enrollment Period: the seven-month window starting three months before your 65th birthday month and ending three months after it.3Medicare.gov. When Does Medicare Coverage Start?
Miss that window and two things happen. You’ll wait until the General Enrollment Period (January 1 through March 31), with coverage starting the first day of the month after you enroll. And you’ll owe a late enrollment penalty. For Part B, the penalty adds 10% to your monthly premium for every full 12 months you were eligible but didn’t sign up, and it lasts as long as you have Part B. For Part A, if you have to pay a premium at all, the 10% increase lasts twice as long as the period you went without coverage.4Medicare.gov. Avoid Late Enrollment Penalties
What Original Medicare Costs in 2026
Part A: Hospital Insurance
Part A covers inpatient hospital stays, skilled nursing facility care, hospice, and some home health services. Most people pay no monthly premium because they or a spouse paid Medicare taxes for at least 10 years (40 quarters).5Medicare. Costs With fewer work credits, the premium in 2026 is $311 per month at 30–39 quarters or $565 per month at fewer than 30.6Centers for Medicare & Medicaid Services. 2026 Medicare Parts A & B Premiums and Deductibles
Even with premium-free Part A, each hospital admission carries a deductible. For 2026, that’s $1,736 per benefit period.6Centers for Medicare & Medicaid Services. 2026 Medicare Parts A & B Premiums and Deductibles It resets each benefit period, so a second hospitalization separated by 60 days could mean paying it again.
Part B: Medical Insurance
Part B covers doctor visits, outpatient procedures, preventive screenings, and durable medical equipment. The 2026 standard premium is $202.90 per month, with an annual deductible of $283.6Centers for Medicare & Medicaid Services. 2026 Medicare Parts A & B Premiums and Deductibles After the deductible, you typically owe 20% coinsurance on covered services, with no annual cap on that spending under Original Medicare.
Higher earners pay more through the Income-Related Monthly Adjustment Amount. The $202.90 premium applies at modified adjusted gross income of $109,000 or less (individual) or $218,000 or less (joint). Above those levels, premiums rise in steps up to $689.90 per month for individuals at $500,000 or more.6Centers for Medicare & Medicaid Services. 2026 Medicare Parts A & B Premiums and Deductibles Your 2024 income determines your 2026 premium.
When you see a provider, confirm they accept Medicare “assignment,” meaning they’ll take the Medicare-approved amount as full payment rather than billing you the difference.
The One Part D Plan on Guam
Only one stand-alone Medicare Part D plan is available in Guam for 2026: AARP Medicare Rx Preferred, offered by UnitedHealthcare. There’s no shopping around against competing plans the way mainland beneficiaries can. If you want Medicare drug coverage on the island, this is the plan.
Enrollment happens during the Annual Enrollment Period, October 15 through December 7, with coverage starting January 1.7Medicare. Joining a Plan Miss it without a Special Enrollment Period and a late enrollment penalty grows the longer you go without creditable drug coverage.
For 2026, Part D plans follow a three-stage structure. A deductible of up to $615, though some plans set it lower. After the deductible, 25% coinsurance on covered drugs until your out-of-pocket spending reaches $2,100. Past that, catastrophic coverage kicks in and you pay nothing for covered drugs the rest of the year.8Medicare.gov. How Much Does Medicare Drug Coverage Cost?
Medigap Coverage on the Island
Because Guam has no Medicare Advantage plans, a Medigap policy is the main way to protect yourself from the costs Original Medicare leaves behind: the 20% Part B coinsurance, hospital deductibles, and other charges that add up with no annual cap.
Several Medigap plan types are sold in Guam, though enrollment is small. Based on the most recent available data, the most popular plans on the island are Plan F, Plan C, Plan G, and Plan N. Plan F and Plan C are closed to anyone who became newly eligible for Medicare after January 1, 2020, but people already enrolled can keep them. For newer enrollees, Plan G and Plan N are the most comprehensive options still open.
When to Buy
Your best window is the Medigap Open Enrollment Period: the six months starting the first day of the month you turn 65 and are enrolled in Part B. During this period, insurers cannot deny you a policy or charge you more because of health conditions.9Medicare.gov. When Can I Buy a Medigap Policy? After it closes, insurers can use medical underwriting, and your health history can affect price and availability. In a market this small, missing that window matters more than it would on the mainland.
Getting Care Off Island
Original Medicare covers care from any participating provider in all 50 states, Washington D.C., and the territories, with no network restrictions.10Medicare.gov. Medicare Coverage Outside the United States If a Guam doctor refers you to a specialist in Hawaii or on the mainland, Medicare pays the same way it would for local care.
Air ambulance transport is narrower. Medicare Part B covers helicopter or fixed-wing air ambulance only when your condition is serious enough that ground transport would threaten survival or seriously endanger health, and either the pickup location is inaccessible by ground or the distance to an appropriate hospital is too great for safe ground transport.11CMS: Medicare Benefit Policy Manual. Chapter 10 – Ambulance Services For hospital-to-hospital transfers, the receiving facility must be the nearest one with the right capabilities. Emergency transfers from Guam to Hawaii may meet those criteria; a routine referral for specialty care won’t, and you’d arrange and pay for commercial travel yourself.
Local Help Paying for Medicare
Several locally administered programs help Guam residents afford what Original Medicare doesn’t fully cover. These matter more here because the private plan market is so thin.
Medically Indigent Program
The Medically Indigent Program (MIP) is a 100% locally funded program administered by the Guam Department of Public Health and Social Services. It covers health care costs for low-income residents who meet income, resource, and residency requirements. If you have Medicare, MIP acts as a payer of last resort, picking up costs Medicare doesn’t pay: coinsurance, copayments, and deductibles. It functions similarly to how Medicaid works on the mainland after Medicare processes a claim.
Medicare Buy-In
Guam’s local government also runs a Medicare Buy-In Program that pays the Part B premium for qualifying low-income residents. With the 2026 premium at $202.90, that assistance amounts to nearly $2,435 a year for someone who qualifies.6Centers for Medicare & Medicaid Services. 2026 Medicare Parts A & B Premiums and Deductibles
Prescription Drug Help
Guam residents are not eligible for the federal Low-Income Subsidy known as Extra Help, which reduces Part D costs for mainland beneficiaries.12Medicaid and CHIP Payment and Access Commission (MACPAC). Medicaid and CHIP in Guam Instead, the local Medicaid program receives funding through the Enhanced Allotment Plan under Section 1935(e) of the Social Security Act, a separate federal allotment specifically to help low-income beneficiaries who qualify for both Medicare and Medicaid pay for prescription drugs.13Medicaid and CHIP Payment and Access Commission (MACPAC). Medicaid and CHIP in the Territories
Where to Get Free Enrollment Help
The Guam Medicare Assistance Program (GUAM MAP) is the island’s State Health Insurance Assistance Program. It provides free, personalized counseling to compare coverage options, understand benefits, and work through enrollment. GUAM MAP runs through the Guam Department of Public Health and Social Services and can be reached at (671) 735-7415.14Centers for Medicare & Medicaid Services. Guam Medicare Assistance Program (GUAM MAP) Contact Details Given how limited the private plan market is, a conversation with a GUAM MAP counselor before your enrollment deadlines is one of the most useful moves you can make, especially if you’re weighing a Medigap policy, checking the sole Part D plan’s formulary, or seeing whether you qualify for local financial assistance.