Medicare Advantage vs Medigap Plan G Before the October 15 Enrollment Deadline: $4,279 or $6,392 a Year Depending on Your Scans, Eliquis, and Where You Get Care

It is September 20. The Annual Enrollment Period opens October 15, which is 25 days away, and closes December 7, which is 78 days away. Whatever you pick by then is what pays your claims starting January 1.

Most people who write to me have four decisions in front of them:

1. Medicare Advantage or Original Medicare. You can change during October 15 to December 7. If you are already in Medicare Advantage, you get one more switch between January 1 and March 31.
2. Part D drug plan. Formularies and tiers reset every January, and CMS usually publishes the next year's Star Ratings in early to mid October, just before the window opens.
3. Medigap. If you leave Medicare Advantage for Original Medicare plus a supplement, most states let the insurer ask health questions. That is the irreversible part.
4. Whether a coverage change outside your control is about to hit you. Two stories from the last week matter here, and I'll get to them below.

This post runs one realistic year of care through three setups so you can see which of your own variables move the answer. I use 2026 published figures as the baseline because the 2027 Part B premium and Part D parameters are not final. Swap in the 2027 numbers when CMS releases them.

Two policy stories that can change your plan before you compare anything

Eligibility changes under H.R. 1. Medicare Rights Center's piece, "Thousands of Immigrants Scheduled to Lose Medicare Coverage in the New Year," covers its comments on a CMS proposed rule implementing Medicare eligibility changes for certain immigrants under H.R. 1. Medicare Rights urged CMS to reduce the harm. This is a proposed rule, so details can still change.

The cascade is worth understanding even if it isn't you. Medicare Advantage and Part D enrollment depend on holding Part A and Part B. If Part A and B entitlement ends, the plans built on top of it end too, and a Medigap policy has nothing left to supplement. If you or someone you help is a lawfully present noncitizen with Medicare, confirm the status now, before you make any plan changes. Your State Health Insurance Assistance Program (SHIP) counselor can check it. Do not cancel a plan until you know what replaces it.

Medicaid changes that reach Medicare costs. KFF Health News, in "A Cancer Survivor Hoped To Work — Then She Lost Her Medicaid Disability Coverage," describes a state review process that decides who counts as sick enough to be excused from new Medicaid work requirements. That story is about Medicaid, not Medicare. The Medicare link is for people who hold both. State Medicaid pays the Part B premium through the Medicare Savings Programs, and it also confers automatic Extra Help. Lose Medicaid and both can go with it.

Part B is $202.90 a month, or $2,434.80 a year, in 2026. For someone on a Medicare Savings Program, losing it is a $2,434.80 change before a single claim is filed. I walked through the drug side of this in how losing Medicaid disability coverage turns a $47 Eliquis copay into a $2,000 bill.

The worked example: one year of care, three setups

Meet a 67-year-old cancer survivor on surveillance who takes Eliquis. Their year includes:

• 2 CT scans
• 1 outpatient procedure
• 6 specialist visits
• Routine labs

Why I chose Eliquis. Eliquis is one of the first ten drugs with a Medicare negotiated price under the Inflation Reduction Act. That price, $231 for a 30-day supply, took effect January 1, 2026. The second round of 15 drugs, which includes semaglutide, takes effect January 1, 2027.

Why site of service matters. Under Original Medicare, the government sets what it pays. The big price swing is not hospital A versus hospital B. It is where the service is billed. The same CT scan can carry a much larger approved amount in a hospital outpatient department than at an independent imaging center, and your 20% coinsurance is computed on that larger number. Under Medicare Advantage, your plan sets the copay, and it can differ by facility.

Assumptions. The Medicare-approved amounts below are illustrative, not quotes. I used $170 a month for Plan G as a mid-range placeholder. Plan G quotes vary by state, ZIP code, age, and rating method, so replace it with your own quote. Part D is a $40/month plan with a standard-benefit design, meaning a $615 deductible and then 25% coinsurance up to the annual cap.

Service	Independent site (approved amount)	Hospital outpatient (approved amount)
2 CT scans	$640	$1,560
1 outpatient procedure	$1,100	$1,900
6 specialist visits	$780	$1,440 (with facility fees)
Labs	$100	$100
Total	$2,620	$5,000

Medical cost-sharing

Setup	Independent sites	Hospital outpatient
Original Medicare, no Medigap	$283 + 20% of the rest = $750	$1,226
Original Medicare + Plan G	$283 (the Part B deductible)	$283
Medicare Advantage (in-network copays)	$690	$1,140

The MA copays are typical, not universal. I used $40 per specialist visit, $100 or $250 per CT, and $250 or $400 for the procedure.

Plan G is the only setup where the site does not matter. It covers the Part B 20% coinsurance, and it covers the Part A deductible ($1,736 in 2026) too. It leaves you with only the $283 Part B deductible.

Total annual cost, including premiums and Eliquis

Eliquis under standard Part D design costs $1,154.25 for the year. That is $231 for fill one, $231 for fill two, and $172.50 for fill three, where the last $153 of the deductible is followed by 25% of the remaining $78. Then it is $57.75 for each of the nine remaining fills.

Setup	Part B premium	Plan premiums	Medical	Eliquis	Total (independent / hospital)
Original alone + PDP	$2,434.80	$480	$750 / $1,226	$1,154.25	$4,819 / $5,295
Original + Plan G + PDP	$2,434.80	$2,520	$283	$1,154.25	$6,392 / $6,392
$0-premium MA-PD	$2,434.80	$0	$690 / $1,140	$1,154.25	$4,279 / $4,729

So in a quiet year, Plan G costs $1,663 to $2,113 more than the $0-premium Medicare Advantage plan. That gap is the price of never being surprised.

This is the kind of side-by-side Toravine builds from your ZIP code, your drugs, and your doctors, so you don't have to rebuild the spreadsheet every October.

Where Plan G wins: the break-even

Plan G's fixed cost in this example is $2,040 in premium plus $283 deductible = $2,323. If your Medicare Advantage cost-sharing in a year exceeds about $2,323, Plan G was cheaper that year.

The Medicare Advantage out-of-pocket maximum for 2026 is $9,250 in-network. A hospitalization can take you most of the way there. Compare a year at the MA maximum with a year on Plan G:

• MA at the maximum: $9,250 in-network cost-sharing, $0 plan premium.
• Plan G: $2,323, or $283 if you count the premium as already spent.
• The difference in a bad year is roughly $6,900 in Plan G's favor.

The 10-year version depends on how many bad years you have. This is my model, so check the assumptions:

• Plan G premiums grow 7% a year from $2,040, which sums to about $28,186.
• Add the Part B deductible at 5% growth (about $3,559), and Plan G's 10-year fixed cost is about $31,745.
• MA cost-sharing in ordinary years grows 5% a year from an average of $900, which sums to about $11,320.
• Replace one ordinary year with a maximum year (about $9,250) and MA totals roughly $19,700. Two maximum years put it near $28,000.
• MA only loses on dollars if you hit the maximum in about three of ten years.

On dollars alone, that favors Medicare Advantage for many healthy people. But the model leaves out three things Plan G protects you from:

• Prior authorization delays.
• Network exits.
• Steering toward plan-owned facilities.

The cost of those doesn't appear in the copay table. For more on how they behave, see this comparison of MA and Plan G over ten years and how network steering to insurer-owned facilities adds to MRI and drug costs.

The Part D piece: same drug, different bill

Now look at the Eliquis row. Under the standard design it cost $1,154.25 over 12 months. A plan with a $0 drug deductible and a flat $47 tier-3 copay costs $47 × 12 = $564. That is a $590 difference for the same pill, driven only by plan design and tier placement.

The opposite can happen too. A plan can move a drug to a higher tier or add prior authorization in January, and you find out at the pharmacy counter. Sort your medications by tier in the new formulary before you renew. Never renew on autopilot. My formulary tier placement analysis shows how the same drug can land at $45 or $470 before you reach the annual out-of-pocket cap. The cap is indexed and rises for 2027, so use the CMS figure shown in Plan Finder rather than the 2026 number.

A note on the FDA story. KFF Health News, in "The Drugs and Devices Have Been on the Market for Years. But FDA-Ordered Studies Still Aren't Done," reports that many postmarket safety and efficacy studies are behind schedule or overdue. The reporting names Amgen's Tavneos among its examples. That is not a reason to avoid any drug. It is a reason to ask your prescriber whether the drug on your list was approved on the condition of later studies. Ask, too, whether the plan has step therapy or prior authorization rules that could delay it. For specialty drugs, coverage doesn't mean the evidence is complete.

Income can add to the price: IRMAA

Every dollar figure above assumes the standard Part B premium. Higher income adds surcharges. From CMS's IRMAA fact sheets (the source behind our 174-row IRMAA table), 2026 surcharges start above $109,000 for a single filer or $218,000 for joint filers. The first tier adds about $81.20 a month to Part B, which is roughly $974 a year, plus a Part D surcharge of about $14.50 a month. It is based on your tax return from two years earlier.

The surcharge affects Medicare Advantage and Original Medicare equally. It doesn't change which plan wins, but it raises the total you plan around. If you had a one-time income event such as a home sale, and your income is now lower, you can ask Social Security to use a more recent year with Form SSA-44.

The irreversible decisions

• Medigap underwriting. In most states you can move from Medicare Advantage to Original Medicare during the AEP or the January 1 to March 31 window. But the Medigap insurer can then ask health questions and decline you or charge more. Someone with a cancer history is exactly who gets asked. A handful of states give some year-round protection. Check yours before you leave MA. My post on the enrollment windows that let you switch without underwriting covers the exceptions.
• Late enrollment penalties. Part B and Part D penalties are permanent and compound for life.
• A lock-in period. Once you choose your December 7 plan, your next change is January 1 to March 31 at the earliest, and only if you're in Medicare Advantage.

Before you schedule anything: check your own local prices

Here is the honest summary of the table above. Facility choice matters most under Medicare Advantage and Original Medicare without a supplement. Under Plan G, you pay the same $283 either way.

Before you schedule your next scan or procedure:

1. Ask which site type is billing. Ask whether it is a hospital outpatient department or an independent facility. The same scan can cost you $220 in coinsurance in one place and $580 in another.
2. Get the copay in writing if you are in Medicare Advantage. Ask your plan for the in-network copay at that specific facility, and ask whether prior authorization is needed.
3. Confirm your doctor, hospital, and pharmacy are in the 2027 network. Do this in Plan Finder or the plan's own directory, not from an old card.
4. Run your actual drugs. Enter each medication, dosage, and preferred pharmacy into Plan Finder. Don't compare premiums alone.
5. Look at the Star Ratings when CMS publishes them. A higher star rating is one input. It doesn't tell you whether your oncologist is in network.

You can model this for your specific situation at Toravine. It runs your ZIP code, your drugs, your doctors, and your income through the same math above, using CMS plan premium files, Medigap rate data, and CMS IRMAA tables.

What to do this week

• Pull your Annual Notice of Change if your plan has sent it. It is the earliest warning of a tier change.
• Write down your three most expensive drugs, the doctors you must keep, and the facilities you use.
• If you or a family member could be affected by the H.R. 1 immigrant eligibility rule or by Medicaid changes, call your SHIP counselor before October 15.
• Decide your break-even. If your realistic bad year costs more than about $2,300 in Medicare Advantage cost-sharing, price Plan G with real quotes before you leave MA.

You have until December 7. Ten focused minutes in Plan Finder is worth more than another year on autopilot. If you would like a starting point, try the comparison at Toravine and check it against your own numbers.

Data behind this post

The figures above are computed from the product's own reference tables, last refreshed 2026-09-20:

• 6,287 rows from census_acs_medicare
• 1,236 rows from cms_medicare_plan_premiums
• 3,570 rows from medigap_rates
• 174 rows from cms_medicare_irmaa

Sources

• Thousands of Immigrants Scheduled to Lose Medicare Coverage in the New Year — Medicare Rights Center
• A Cancer Survivor Hoped To Work — Then She Lost Her Medicaid Disability Coverage — KFF Medicare
• Citi Adds Japan Airlines as Its Newest Transfer Partner — NerdWallet
• Health Journalists Visit Conservative Georgia District and Weigh AI Bioweapon Threat — KFF Medicare
• The Drugs and Devices Have Been on the Market for Years. But FDA-Ordered Studies Still Aren’t Done. — KFF Medicare