Medicare Advantage vs Supplement 2027 Calculator

This Medicare Advantage vs supplement calculator compares the two ways to cover what Original Medicare leaves behind: a private Advantage plan with low premiums and a yearly out-of-pocket cap, or a Medigap supplement with a higher premium and almost no cost-sharing. Enter your premium and expected medical use to see which is cheaper for your year.

Medicare Advantage (Part C)

A private plan that replaces Original Medicare and must cover everything Parts A and B cover. Most are HMOs or PPOs with a provider network, monthly premiums commonly $0–$50 on top of your Part B premium, and a hard in-network out-of-pocket maximum — $9,350 for 2026 under the CMS limit. Drug, dental, vision and hearing extras are usually bundled in. The trade-offs are network restrictions and prior authorisation on some services.

Medigap (Supplement)

A supplement sits on top of Original Medicare rather than replacing it, so any provider who accepts Medicare accepts your plan — no network, no referrals, and coverage travels with you nationwide. Plan G is the most popular for people newly eligible: roughly $150–$300 a month depending on age, state and rating method, after which you pay only the annual Part B deductible (about $283 in 2026 — confirm the current figure on Medicare.gov). Note that Medigap does not include drug coverage, so budget a separate Part D premium.

Medicare Advantage vs Supplement: Which Costs Less?

The comparison is a premium-versus-exposure trade, and the arithmetic is simple. Suppose Medigap Plan G costs $200 a month more than a $0-premium Advantage plan: that is $2,400 a year of certain extra cost. In exchange you remove an out-of-pocket exposure that can reach $9,350. So:

• A low-use year — a few office visits and routine labs — Advantage almost always wins, often by $2,000 or more.
• A high-use year — a hospital stay, cancer treatment, joint replacement — Medigap wins, because you hit the Advantage cap and pay $9,350 while the supplement holder pays the Part B deductible.
• The break-even sits near $2,400 of Advantage cost-sharing. Below it Advantage is cheaper; above it Medigap is.

That is why the decision is less about this year's premium than about whether you could absorb a bad year, and how predictable you need the bill to be. Run both scenarios in the calculator above rather than comparing premiums alone.

Switching — and the Underwriting Trap

You can move between Advantage plans, or drop Advantage for Original Medicare, during Annual Open Enrollment (15 October – 7 December) or the Medicare Advantage Open Enrollment Period (1 January – 31 March). Getting a Medigap policy is a different matter, and it is where people get stuck.

• Medigap Open Enrollment is a one-time six-month window that starts the month you are both 65 or older and enrolled in Part B. During it, insurers must sell you any plan they offer at the standard price regardless of health.
• After that window, most states let insurers use medical underwriting: they can charge more or decline you outright for pre-existing conditions.
• Trial right — if you joined an Advantage plan when first eligible at 65, you have 12 months to switch back to Original Medicare with a guaranteed-issue right to a Medigap policy.
• State exceptions — Connecticut, Massachusetts, Maine and New York give broader guaranteed-issue or annual switching rights, so the trap is far weaker there.

Practical consequence: choosing Advantage at 65 is easy to enter and can be hard to leave, while choosing Medigap first keeps both doors open. Weigh that alongside the cost figures the calculator produces.

Drug Coverage: The Part D Cost the Comparison Usually Misses

Premium comparisons between Advantage and Medigap often quietly omit prescriptions, and it is the single most common reason a carefully budgeted year comes in over. Most Advantage plans bundle Part D drug coverage into the plan premium. A Medigap policy legally cannot include drug coverage, so a supplement holder must buy a standalone Part D plan separately — typically another $20 to $60 a month on top of the Medigap premium. Add that to the Medigap side before comparing, or the supplement looks cheaper than it is.

The good news is that the drug-side downside is now capped. Under the Inflation Reduction Act redesign, Part D out-of-pocket spending is limited to $2,100 for 2026 (up from the $2,000 cap introduced in 2025, indexed to Part D drug expenditure growth), after which covered drugs cost you nothing for the rest of the calendar year. That cap applies whether your drug coverage arrives bundled inside an Advantage plan or as a standalone plan alongside Medigap, so it does not tilt the comparison — but it does mean a bad drug year is no longer unbounded on either path. The figure is published in the CMS Final CY 2026 Part D Redesign Program Instructions. One more trap: going without creditable drug coverage triggers a permanent late-enrolment penalty of 1% of the national base beneficiary premium for every month you delayed, so skipping Part D to save the premium is rarely the saving it appears to be.

Source and Disclaimer

Figures follow medicare.gov and CMS published data for 2026; 2027 premiums and limits are projections until CMS publishes them each autumn. Verify your own plan costs on Medicare Plan Finder before enrolling.

Source: medicare.gov, CMS. Last updated: 22 August 2026.