Medigap vs Medicare Advantage: How to Choose for 2027 (and the Switching Trap)

Medigap and Medicare Advantage are two different ways to fill the gaps in Medicare. Medigap sits on top of Original Medicare: you pay a higher monthly premium, and in return you pay little or nothing when you get care, from any doctor in the U.S. who takes Medicare. Medicare Advantage replaces Original Medicare with a private plan: premiums are low (CMS projects an average of $12.00 a month in 2027), but you use a network, may need prior approval, and can owe up to $9,850 in-network in a bad year. The choice is harder to undo than most people expect, because after your first Medigap window an insurer can usually turn you down for health reasons. Here is how to decide during Open Enrollment, October 15 to December 7, 2026.

The Short Answer

• Medigap (plus a separate Part D drug plan) costs more each month but makes bad health years cheap and lets you see any provider in the U.S. that takes Medicare. No referrals, and in most cases no prior authorization.
• Medicare Advantage costs less each month, often bundles drug, dental, vision and hearing extras, and caps your yearly spending. The 2027 federal cap is $9,850 in-network and $14,800 combined for PPOs, up from $9,250 and $13,900 in 2026.
• The trap: your guaranteed right to buy any Medigap policy lasts 6 months from when you are 65 or older and have Part B. Leave it and switch later, and in most states an insurer can ask health questions and say no.
• The escape hatch: if you joined Medicare Advantage when first eligible at 65, a federal "trial right" lets you switch back to Original Medicare and buy any Medigap policy within the first year.
• New 2027 Medigap numbers: the high-deductible Plan G (and F) deductible is $3,050, up from $2,950. The 2027 Part B premium and deductible are not out yet; expect them around mid-November.

How Each Path Works

Path 1: Original Medicare + Medigap + Part D. Original Medicare is Part A (hospital) and Part B (doctors and outpatient care). On its own it has no yearly limit on what you pay. After the Part B deductible you usually pay 20% of the Medicare-approved amount, with no ceiling. A Medigap policy, sold by a private insurer, pays some or all of those leftover costs. Medigap plans sold after 2005 do not cover prescription drugs, so you add a stand-alone Part D plan. You pay three premiums: Part B, Medigap and Part D.

Path 2: Medicare Advantage (Part C). A private plan approved by Medicare takes over your Part A and Part B coverage. Most plans include Part D. You still pay the Part B premium, plus the plan's premium if it has one; some plans charge $0, and some may help pay all or part of your Part B premium. In exchange the plan sets its own copays, its own network and its own rules for prior authorization and referrals.

You cannot combine them. Medicare & You 2027 says it is illegal to sell you a Medigap policy while you are in a Medicare Advantage plan unless you are switching back to Original Medicare.

Medigap vs Medicare Advantage Side by Side

Sources: Medicare & You 2027 ("At a glance" table); Medicare.gov, Choosing a Medigap Policy (March 2026); CMS 2027 MA/Part D press release (Sep 28, 2026); CMS Final CY 2027 Part C Bid Review memo (Apr 22, 2026); CMS CY 2027 Rate Announcement, Table V-2.

Medicare Advantage in 2027: Limits, Premiums, Plans

CMS sets a ceiling on the yearly out-of-pocket limit every Medicare Advantage plan must have. For 2027 that ceiling went up by $600 in-network and $900 combined.

Source: CMS HPMS memos, Final CY 2026 Part C Bid Review Memorandum (Apr 16, 2025) and Final CY 2027 Part C Bid Review Memorandum (Apr 22, 2026), Table 3. Changes are our arithmetic.

These are maximums. Plans can and often do set lower limits; KFF (secondary source) found the average in-network limit in 2026 was $5,421. Your plan's actual number is in its Summary of Benefits. The limit covers Part A and Part B services only. Drug costs run under Part D, which has its own 2027 cap of $2,400.

From CMS's September 28, 2026 release on 2027 plans:

• Average Medicare Advantage premium: projected to fall from $14.37 in 2026 to $12.00 in 2027, a 16.5% decline. This is a weighted average across all plans, including those with drug coverage.
• Enrollment: about 34 million in 2027, roughly 47.4% of people with Medicare, based on plan projections. CMS notes those projections have historically come in low.
• Plans: about 5,532 nationally, versus 5,553 in 2026. More than 99% of beneficiaries can get at least one plan, and 97% can choose from 10 or more.
• About eight in 10 current Medicare Advantage members can stay in their plan at the same or a lower premium.

Plan exits. CMS's release gives the net plan count but no national number of plans ending or enrollees affected for 2027. If your plan is leaving Medicare or your area, your plan must tell you, and you get a federal guaranteed issue right to buy Medigap Plan A, B, D or G (plus C or F if you were eligible for Medicare before 2020), as long as you go to Original Medicare. Apply no later than 63 days after your plan coverage ends. Read your Annual Notice of Change carefully this fall.

Medigap Plans for 2027: G, N and High-Deductible G

Medigap plans are standardized by letter: A, B, C, D, F, G, K, L, M and N in most states. Every Plan G pays the same benefits whichever insurer sells it; only the price differs. Massachusetts, Minnesota and Wisconsin use their own standardized designs.

Plans C and F are closed to anyone new to Medicare on or after January 1, 2020. Federal law (Social Security Act section 1882(z)) bars selling newly eligible people a policy that covers the Part B deductible. If you were eligible before 2020, you may still buy C or F. Everyone else gets D and G instead, which are the same minus the Part B deductible.

Sources: Medicare.gov, Choosing a Medigap Policy (March 2026), plan chart; CMS, Deductible Amount for Medigap High Deductible Options F, G & J for Calendar Year 2027 (October 2026).

Plan G vs Plan N. Plan N's premium is often lower because you share small costs, but check quotes in your area. The bigger difference is excess charges. A doctor who doesn't accept Medicare assignment can, in many cases, bill up to 15% above the Medicare-approved amount (the "limiting charge"). Plan G pays that; Plan N does not. If most of your doctors accept assignment and you rarely visit the ER, N can save money. If you see many specialists or live where non-participating doctors are common, G is the simpler choice.

High-deductible Plan G. You pay Medicare-covered costs up to the deductible, $3,050 in 2027, before the policy pays. CMS raises it each fall by the CPI-U; the 2027 increase was 3.40%. High-deductible G is open to people new to Medicare on or after January 1, 2020; the high-deductible Plan F is only for those eligible earlier. Not every state or insurer offers it.

Plans K and L pay a share of costs and cap your spending. Their 2027 limits are $8,360 (K) and $4,180 (L), up from $8,000 and $4,000.

How Medigap premiums are priced. Each insurer picks one of three methods: community-rated (same premium regardless of age), issue-age-rated (based on your age when you buy, and doesn't rise because you get older) or attained-age-rated (rises as you age; cheapest at first, can become the most expensive). Premiums also vary by state, insurer and discounts, and there is no official national average. Get quotes through Medicare.gov or your State Health Insurance Assistance Program (SHIP), and ask which pricing method each insurer uses.

The Switching Trap: Medical Underwriting

Your Medigap Open Enrollment Period is 6 months, starting the first month you are 65 or older and have Part B. It happens once and does not repeat. During it, an insurer must sell you any Medigap policy it offers in your state, cannot use medical underwriting, and cannot charge more for health problems. If you delayed Part B because you had job-based coverage, the window starts when you enroll in Part B.

After that window, in most cases an insurer may ask health questions, charge more, or refuse to sell you a policy, unless you have a guaranteed issue right. Federal guaranteed issue rights include:

• Your Medicare Advantage plan leaves Medicare, stops serving your area, or you move out of its service area, and you go back to Original Medicare.
• Your employer or union retiree plan that pays after Medicare is ending, your Medigap insurer goes bankrupt, or your plan or insurer misled you.
• Trial right 1: you joined a Medicare Advantage plan when you were first eligible for Medicare Part A at 65, and within the first year you want to switch to Original Medicare. You can buy any Medigap policy sold in your state.
• Trial right 2: you dropped a Medigap policy to join a Medicare Advantage plan for the first time, and you've been in it less than a year. You can get your old policy back if the same insurer still sells it, or buy Plan A, B, D or G (C or F if eligible before 2020).

For most of these, apply no later than 63 days after your old coverage ends. Medicare's guide notes the trial-right window may last an extra 12 months in some situations.

State rules. Federal law is the floor. Some states have extra Medigap open enrollment periods or give you more chances to change policies, and Massachusetts, Minnesota and Wisconsin run their own systems. These rules differ and change, so check the "Choosing a Medigap Policy" guide and your state insurance department before you rely on one.

Your 2027 Enrollment Windows

• October 15 to December 7, 2026: Open Enrollment. Join, switch or drop a Medicare Advantage or Part D plan, or go back to Original Medicare. Changes start January 1, 2027. Full details in our Medicare Open Enrollment 2026 guide.
• January 1 to March 31, 2027: Medicare Advantage Open Enrollment. Only if you are already in a Medicare Advantage plan. You can make one change: switch to another Medicare Advantage plan, or go to Original Medicare and join a stand-alone drug plan. You cannot use it to move from Original Medicare into Medicare Advantage.
• Medigap has no annual window. You can apply any time, but outside your first 6 months or a guaranteed issue right, approval depends on the insurer's underwriting. Apply for Medigap and get approved before you leave a Medicare Advantage plan.

Hypothetical Cost Example: Good Year vs Bad Year

The table below is an illustration, not a quote. It uses the 2026 Part B premium ($202.90 a month, $2,434.80 a year) and deductible ($283) because the 2027 amounts have not been announced. The Medigap premiums and the Medicare Advantage copays are round-number assumptions, not averages; your real quotes may be far higher or lower. Drug costs are left out because all three paths face the same $2,400 Part D cap in 2027.

Our arithmetic. Inputs: CMS 2026 Part B figures; CMS 2027 average MA and Part D premiums (Sep 28, 2026); CMS 2027 high-deductible G and MOOP figures. Medigap premiums and MA copays are assumptions. Assumes providers accept Medicare assignment and in-network care.

What this shows: in this example, Medicare Advantage wins in a healthy year by a few hundred to a couple of thousand dollars. In a bad year the order flips, and the gap depends almost entirely on your plan's own limit. A Medicare Advantage plan with a $5,000 limit would total $7,578.80 in the bad year, still above Plan G. High-deductible G sits between the two. Over a long retirement, most people have some bad years. Higher earners also pay IRMAA surcharges on either path; our healthcare costs in retirement guide covers the full budget.

Decision Checklist: Which Fits You

Medigap is usually the better fit if you:

• Are in your 6-month Medigap window now, or have a guaranteed issue right.
• Have a chronic condition, a cancer history, or expect specialists, surgery or hospital stays.
• Split the year between states, travel often, or want access to a specific out-of-area hospital.
• Want predictable costs and no prior authorization hassles, and can afford a higher premium.

Medicare Advantage is usually the better fit if you:

• Need a low monthly premium and can absorb the plan's out-of-pocket limit in a bad year.
• Are happy with doctors and hospitals in a local plan's network and stay in one area.
• Value dental, vision or hearing extras and a single card for medical and drugs.
• Are 65 and new to Medicare, so the trial right protects you for the first year.

Before you switch, check: your doctors and hospitals in the plan's directory; your drugs on the formulary (see our Part D 2027 guide); the plan's in-network limit; prior authorization rules for services you use; and, if you are leaving Medigap, whether you could buy it back. Free one-on-one help is available from your SHIP at shiphelp.org or 1-800-MEDICARE.

FAQ

Can I switch from Medicare Advantage to Medigap?
Yes, during Open Enrollment (October 15 to December 7) or the Medicare Advantage Open Enrollment Period (January 1 to March 31). But unless you are in your first-year trial right or another guaranteed issue situation, the Medigap insurer can usually use medical underwriting and may deny you. Get approved for Medigap before you drop your plan.

What is the Medicare Advantage out-of-pocket maximum for 2027?
The highest a plan may set is $9,850 for in-network services and $14,800 combined for PPOs, up from $9,250 and $13,900 in 2026. Many plans set lower limits.

What is the high-deductible Plan G deductible for 2027?
$3,050, up from $2,950 in 2026, per CMS. The same amount applies to high-deductible Plan F.

Is Plan G or Plan N better?
Plan G covers everything Plan N does plus Part B excess charges and without office or ER copays. Plan N's premium is often lower. N fits people whose doctors accept Medicare assignment and who make few visits.

Can I still buy Plan F?
Only if you were eligible for Medicare before January 1, 2020. People new to Medicare since then can buy Plan G, which is the same minus the Part B deductible.

Do I need a Medigap policy for my spouse too?
Yes. A Medigap policy covers one person, so each spouse buys their own.

What will Part B cost in 2027?
Not announced as of October 11, 2026. CMS released the 2026 figures on November 14, 2025, so expect 2027 numbers around mid-November. See our Part B premium page.

Sources & Methodology

• CMS, Medicare Advantage and Medicare Prescription Drug Programs Expected to Remain Stable in 2027 (Sep 28, 2026), for 2027 average premiums, enrollment, plan counts and Open Enrollment dates.
• CMS HPMS memo, Final CY 2027 Part C Bid Review Memorandum (Apr 22, 2026) and the Final CY 2026 memo (Apr 16, 2025), Table 3, for the maximum out-of-pocket limits.
• CMS, Medigap High Deductible Options F, G & J for CY 2027 and Out-of-Pocket Limits for Medigap Plans K & L for CY 2027.
• CMS CY 2027 Rate Announcement (Apr 6, 2026), Table V-2, for the $2,400 Part D out-of-pocket threshold.
• Medicare.gov, Choosing a Medigap Policy (March 2026), for plan benefits, Plan N copays, pricing methods, the Medigap Open Enrollment Period and guaranteed issue rights.
• Medicare & You 2027, for the Original Medicare vs Medicare Advantage comparison, the limiting charge and enrollment periods; 42 CFR 422.62 for the one-change rule.
• Social Security Act section 1882 (42 U.S.C. 1395ss), for the Medigap open enrollment protection and the 2020 Plan C/F rule.
• CMS, 2026 Medicare Parts A & B Premiums and Deductibles, for the Part B figures in the example.
• Secondary context: KFF, Medicare Advantage in 2026, for the average 2026 in-network limit.

Method notes. Year-over-year changes and the cost example are our arithmetic from the official figures. The cost example mixes 2026 Part B amounts with 2027 plan figures because 2027 Part B amounts are not yet published, and its Medigap premiums and Medicare Advantage copays are assumptions. CMS has not published a national count of Medicare Advantage plans ending in 2027, and there is no official national average Medigap premium, so we quote neither.

This article is for general information and is not financial, tax, legal or insurance advice. Figures are from CMS, Medicare.gov and federal law, checked against the primary sources on 2026-10-11. Plan premiums, networks, benefits and state Medigap rules vary; confirm details with the plan, Medicare.gov or your SHIP before you enroll or switch. Wealthy Pot is not affiliated with Medicare or any government agency and does not sell insurance.