Medicare Advantage vs. Original Medicare: A 2026 Guide

Last reviewed: July 2026

Two ways to get the same entitlement

Everyone with Medicare has the same underlying entitlement: Part A (hospital insurance) and Part B (medical insurance). The choice is about how that entitlement is delivered. With Original Medicare, the federal government pays your providers directly and you can add separate pieces — a Part D drug plan and, often, a Medigap supplement. With Medicare Advantage (Part C), a private insurer contracts with Medicare to bundle your Part A and B benefits into one plan, usually with drug coverage built in. In 2026, about 55% of eligible beneficiaries are in Medicare Advantage, according to KFF — so both routes are mainstream, and neither is automatically better. The tradeoffs below are structural, and which ones matter most depends on your health, budget, and location. (New to the alphabet soup? Start with our guide to Medicare's parts.)

Provider access: any-willing-provider vs. networks

Original Medicare has no network. You can see any doctor or hospital in the U.S. that accepts Medicare — most do — without referrals, and coverage travels with you across state lines. Medicare Advantage plans, by contrast, are built around provider networks, usually as HMOs or PPOs. HMOs generally cover only in-network care (except emergencies), and in most cases require referrals to see specialists. PPOs cover out-of-network care but at higher cost. Networks can change during the year, and a plan that includes your doctors today may not next year. For people who travel frequently, split time between states, or rely on a specific specialist or cancer center, network design is often the single most consequential difference between the two routes.

Prior authorization: who decides before you get care

In Original Medicare, very few services require advance approval; providers generally deliver care and bill Medicare afterward. Medicare Advantage works differently: KFF reports that in 2026, 99% of MA enrollees are in plans that require prior authorization for some services — most commonly higher-cost care such as hospital stays and skilled nursing facility care. The volume is substantial: MA insurers made nearly 53 million prior authorization determinations in 2024, denying about 7.7% of requests in full or in part. Notably, only a small share of denials were appealed — about 11.5% — but among those that were, more than 80% were overturned. Prior authorization is one of the main tools MA plans use to control costs — which helps fund their extra benefits — but it can also mean delays or denials that Original Medicare enrollees rarely encounter.

Out-of-pocket exposure: a cap vs. no cap

This is the tradeoff many people find most counterintuitive. Medicare Advantage plans must cap your in-network out-of-pocket spending on Part A and B services. For 2026, CMS allows that cap to be as high as $9,250 in-network, though plans can set it lower — the enrollee average is about $5,421, per KFF. Once you hit the cap, the plan pays 100% of covered medical services for the rest of the year.

Original Medicare, on its own, has no out-of-pocket maximum. In 2026, you pay a $1,736 Part A deductible per hospital benefit period, a $283 annual Part B deductible, and then typically 20% coinsurance on Part B services — with no ceiling. A serious illness could mean unlimited 20% shares of very large bills. That is why most people on Original Medicare pair it with either a Medigap policy (which fills most of these gaps in exchange for a monthly premium) or other coverage such as employer retiree benefits or Medicaid. Meanwhile, most Medicare Advantage enrollees pay little or nothing beyond the standard Part B premium ($202.90/month in 2026): KFF finds 75% of enrollees in individual MA plans with drug coverage pay no additional plan premium. The pattern, roughly: Original Medicare plus Medigap tends to mean higher fixed monthly costs and very predictable bills; Medicare Advantage tends to mean lower monthly costs but more cost-sharing, and more exposure, when you actually use care.

Drug coverage and extra benefits

Most Medicare Advantage plans include Part D drug coverage; with Original Medicare you buy a stand-alone Part D plan separately. Either way, the Part D out-of-pocket cap — $2,100 in 2026 — applies to covered drugs. Medicare Advantage plans also commonly offer benefits Original Medicare doesn't cover: in 2026, nearly all individual-plan enrollees have some dental, vision, and hearing coverage, and most have fitness benefits. The scope and dollar limits of these extras vary widely by plan, so it's worth reading the actual benefit details rather than the headline.

The Medigap question: a door that can close

Medigap deserves special attention because the timing rules are unforgiving. You cannot use a Medigap policy with a Medicare Advantage plan — Medigap only works alongside Original Medicare. Your one federally guaranteed window to buy any Medigap policy sold in your state, regardless of health, is the six-month Medigap Open Enrollment Period that starts when you're 65 or older and enrolled in Part B. Outside that window, in most states, insurers can use medical underwriting — meaning they can charge more or decline you based on your health, unless you qualify for a specific guaranteed-issue right. One such right is the "trial right": people who joined Medicare Advantage when first eligible generally have 12 months to switch to Original Medicare and buy a Medigap policy without underwriting. A handful of states have broader protections, but in much of the country, choosing Medicare Advantage now can make moving to Original Medicare plus Medigap difficult or expensive later, even though switching to Original Medicare itself is always allowed during enrollment windows. Our Medigap basics guide covers this in more depth.

When you can switch

The choice isn't permanent, but it isn't continuously open either. During Medicare Open Enrollment (October 15–December 7) anyone can move between Original Medicare and Medicare Advantage, or change plans, effective January 1. Medicare Advantage enrollees get a second window (January 1–March 31) to switch MA plans or drop to Original Medicare. Certain life events trigger Special Enrollment Periods. See our enrollment periods guide for details — and remember the Medigap underwriting issue above, which operates on its own separate clock.

How to think about the choice

There is no universally right answer, because the two routes price risk differently and restrict access differently. Questions that tend to matter most: Are your doctors and hospitals in a given plan's network, and how would you feel if that changed? Are your prescriptions on the plan's formulary? Do you travel or live in multiple states? Can your budget handle a bad year at the plan's out-of-pocket maximum — or, on Original Medicare, can it handle a Medigap premium every month? How much do dental, vision, and hearing extras matter to you? These are personal-circumstance questions, and the honest answer is to run your own numbers. Free, unbiased help exists: the plan-comparison tools at Medicare.gov, 1-800-MEDICARE, and one-on-one counseling from your State Health Insurance Assistance Program (SHIP).

Sources

This guide is for general education only and is not medical, legal, insurance, or financial advice. For decisions about your own coverage, use official sources or free help from your SHIP counselor.