Medicare 2026

Medicare Advantage vs Medigap: Honolulu Structure Guide

In Honolulu, the choice between Original Medicare with a Medigap plan and Medicare Advantage is one of the biggest decisions a new enrollee will make. The two paths are built differently, and understanding how each is structured can save you a lot of second-guessing later. This guide walks through what actually separates them, so you can think it through with clear eyes.

Two different structures, not two versions of the same thing

Original Medicare is the federal program: Part A (hospital) and Part B (doctor and outpatient). You can see any provider in the U.S. who accepts Medicare, and there is no network. But Original Medicare alone has no yearly out-of-pocket limit, which is why many people add a Medigap policy (also called Medicare Supplement) to help cover the coinsurance and deductibles Medicare doesn't pay.

Medicare Advantage (Part C) is different. It's Medicare delivered through a private insurance company approved by CMS. The plan takes over your Part A and Part B coverage and usually folds in Part D drug coverage too. Most Advantage plans use a network of doctors and hospitals, and many require referrals or prior authorization for certain services.

What Medigap actually does — and doesn't do

Medigap sits alongside Original Medicare and pays some or all of the "gaps" — things like the Part A hospital coinsurance or the 20% Part B coinsurance. Medigap plans are standardized by letter (Plan G and Plan N are common examples), so a Plan G from one carrier covers the same core benefits as a Plan G from another.

A few things Medigap does not do:

• It does not include prescription drug coverage. If you go this route, you'd typically add a stand-alone Part D plan.
• It does not include extras like routine dental, vision, or hearing.
• It generally cannot be paired with a Medicare Advantage plan — you pick one path or the other.

One important detail: when you first sign up for Part B at 65, you get a one-time Medigap Open Enrollment window where insurers must sell you a policy regardless of health. Outside that window, in most states you can be medically underwritten, which may affect whether you can switch later.

How Medicare Advantage is structured

Medicare Advantage plans bundle your coverage under one card. Most include Part D, and many offer extra benefits like dental, vision, hearing, or fitness programs. Every Advantage plan is required to have an annual out-of-pocket maximum for in-network Part A and B services, which is a built-in ceiling Original Medicare alone doesn't have.

The trade-off is the network. HMOs generally require you to stay in-network except for emergencies. PPOs allow out-of-network care at a higher cost. If you travel often, split time between Hawaii and the mainland, or want to keep a specific specialist, it's worth checking a plan's network rules carefully before enrolling.

What's available in Honolulu

Honolulu is in Honolulu County, where Medicare plan availability is set at the county level by CMS. That means the number of Medicare Advantage plans, stand-alone Part D plans, and Medigap carriers you can choose from is determined by county, not by ZIP code or neighborhood. You can see the current list for your address using the Plan Finder at medicare.gov.

Costs and rules that apply either way

Some figures apply no matter which path you choose:

• Part D has an annual out-of-pocket cap on covered drugs of $2,100 in 2026 and $2,400 in 2027.
• The Part D maximum deductible is $615 in 2026 and $700 in 2027.
• The coverage gap ("donut hole") is gone as of 2025; Part D now has three phases.
• The Medicare Prescription Payment Plan lets you spread drug costs across the year in monthly installments instead of paying at the pharmacy counter.
• IRMAA surcharges on Part B and Part D begin above $109,000 in income for a single filer.

And two dates to remember:

• Annual Enrollment Period: October 15 – December 7.
• Medicare Advantage Open Enrollment: January 1 – March 31 (for people already in an Advantage plan).

Common mistakes to avoid

The most common misstep is treating the two paths as interchangeable. They aren't. Switching from Medicare Advantage to Original Medicare + Medigap later in life can be difficult if you're subject to medical underwriting on the Medigap side. Another mistake is skipping Part D when you first become eligible — if you go without creditable drug coverage, a late-enrollment penalty can follow you for as long as you have Part D.

Finally, don't assume a plan that works for a friend or neighbor works for you. Your doctors, your prescriptions, and your travel habits all matter.