Medicare 2026

Original Medicare with Medigap vs. Medicare Advantage: A Cost-Structure Way to Think It Through

When people compare Original Medicare plus a Medigap policy to Medicare Advantage, the conversation often jumps straight to networks, extra benefits, or a specific plan someone's neighbor picked. That's fine to circle back to, but it skips the part that shapes your budget the most: how each path stacks its cost pieces. Once you can see the shape of the costs, the rest of the decision gets easier.

Here's a plain-English walk through the cost architecture of both routes, using program-level facts for 2026 and 2027 where they've been published. Nothing here is a recommendation — just a framework you can use.

The four cost "buckets" in Medicare

Every path through Medicare involves some combination of four things:

1. Premiums — what you pay monthly whether or not you use care. 2. Deductibles — what you pay before coverage starts paying its share. 3. Cost-sharing — copays or coinsurance when you actually use services. 4. An out-of-pocket ceiling — the maximum you could be on the hook for in a year.

Original Medicare, Medigap, Part D, and Medicare Advantage each fill these buckets differently. That's really the whole story.

Path A: Original Medicare + a Medigap policy + a Part D plan

Under Original Medicare (Parts A and B), the federal program itself handles most of the cost-sharing rules:

• Part A (hospital) has a per-benefit-period deductible and day-based coinsurance for long stays. Most people pay no Part A premium because of their work history.
• Part B (doctors, outpatient) has a standard monthly premium set each year by CMS, an annual deductible, and then typically 20% coinsurance on covered services — with no annual cap on that 20% by itself.
• Part D (drugs) is a separate premium for a stand-alone drug plan. In 2026, Part D includes a $2,100 annual out-of-pocket cap on covered drugs, plus an option to spread those costs monthly through the Medicare Prescription Payment Plan.

That uncapped 20% on Part B is why most people who choose Original Medicare pair it with a Medigap (Medicare Supplement) policy. Medigap is sold by private insurers using standardized federal plan letters. In exchange for an additional monthly premium, a Medigap plan picks up some or all of the deductibles, copays, and coinsurance that Original Medicare leaves to you. Different lettered plans cover different pieces, and premiums vary by insurer, age, location, and how the plan is rated.

So the cost structure of Path A looks like:

• Part B premium + Medigap premium + Part D premium
• Very predictable out-of-pocket exposure once Medigap is in place
• Drug costs capped at the Part D limit
• Higher fixed monthly cost, lower variable cost when care is used

One nuance worth knowing: Medigap has its strongest federal enrollment protections during your Medigap Open Enrollment Period — the six months starting when you're 65 or older and enrolled in Part B. Outside that window, insurers in most of the country can use medical underwriting to decide whether to offer you a policy and at what price. That's a cost-structure issue as much as an enrollment issue, because it can affect what Medigap costs you later if you try to switch in.

Path B: Medicare Advantage (Part C)

A Medicare Advantage plan is offered by a private insurer under contract with Medicare and bundles your Part A and Part B coverage — usually with Part D built in. You still owe the Part B premium; the plan may charge an additional premium on top, or it may not.

The defining cost feature of Medicare Advantage is the annual out-of-pocket maximum for Part A and B services, which CMS sets an upper limit on each year. Once you hit your plan's max, in-network Part A and B cost-sharing for the rest of the year is covered. Drug costs run through the same Part D cap — $2,100 in 2026 and $2,400 in 2027.

The cost structure of Path B looks like:

• Part B premium + any plan premium
• Copays and coinsurance as you use services, until you reach the plan's out-of-pocket max
• Lower or sometimes $0 additional premium, higher variable cost when care is used
• Extra benefits some plans include are outside the Medicare-defined cost buckets and vary widely

Medicare Advantage plans typically use networks and may require referrals or prior authorization for certain services. Those aren't dollar costs, but they shape when and how you access care, which in turn affects what you spend.

Two ways to picture the trade-off

The "steady bill" shape. Path A tends to convert medical costs into monthly premiums. You pay more every month, but a hospital stay or a run of specialist visits doesn't move your budget much.

The "pay as you go" shape. Path B tends to keep monthly costs lower and shift more of the spending to the moments you use care — with a hard ceiling so a bad year can't be unlimited.

Neither shape is universally better. A person who rarely sees a doctor may value the lower monthly outlay. A person who expects frequent specialist care, or who simply sleeps better with predictable bills, may value the steadier structure. Your own health, cash flow, and tolerance for surprise are the variables.

A few honest complications

• Part D is in both paths. The Part D out-of-pocket cap ($2,100 in 2026, $2,400 in 2027) applies whether your drug coverage is stand-alone or bundled inside a Medicare Advantage plan.
• IRMAA. Higher-income enrollees pay income-related surcharges on Part B and Part D. That applies under either path.
• Switching later. Moving from Medicare Advantage back to Original Medicare during an allowed enrollment window is generally straightforward, but adding a Medigap policy at that point may involve underwriting depending on the circumstances. Factor that into a long-term view, not just year one.

Where to get help

This is an independent educational overview, not government material and not a recommendation of any plan. For official information and personalized help:

• Medicare.gov — the federal program's site, including the Plan Finder.
• 1-800-MEDICARE (1-800-633-4227) — 24/7 help line.
• Your State Health Insurance Assistance Program (SHIP) — free, unbiased one-on-one counseling. You can find your local SHIP through Medicare.gov.

Start with the cost shape that fits your life, then look at specific plans available where you live. The order matters more than most people realize.