Medicare Advantage $0 Premium vs Medigap Plan G $150/Month: The 10-Year Out-of-Pocket Cost Comparison Before March 31
Medicare Advantage $0 Premium vs Medigap Plan G $150/Month: The 10-Year Out-of-Pocket Cost Comparison Before March 31
You have until March 31, 2026 to make one change to your Medicare Advantage plan. That's it — one switch, and whatever you land on takes effect April 1. But before you decide whether to stay, switch plans, or seriously consider whether Medicare Advantage is still the right structure for you, there's a calculation most people never actually run: what does my current plan cost compared to Original Medicare plus a Medigap policy over 10 years?
This post does that math. Not in the abstract — with the actual 2026 numbers, across three realistic health-use scenarios, and with an honest accounting of where IRMAA surcharges and the Medigap underwriting trap change everything.
The Decision You're Actually Making Right Now
The Medicare Advantage Open Enrollment Period (MA OEP), which runs January 1 through March 31 each year, lets you make exactly one coverage change. As the Medicare Rights Center noted in its March 2026 guidance, that means you can switch from one MA plan to another, or drop MA entirely and return to Original Medicare. What it does not let you do is guarantee you can pick up a Medigap policy.
That distinction matters enormously and we'll come back to it.
Right now, the question most beneficiaries face going into March 31 is deceptively simple: is my $0-premium Medicare Advantage plan actually cheaper than Original Medicare with a Medigap supplement? Let's find out.
The 2026 Baseline Numbers
Before comparing plans, let's anchor to current costs:
| Cost Component | 2026 Amount |
|---|---|
| Part B standard premium | $185/month ($2,220/year) |
| Part B deductible | $257/year |
| Part A deductible (per benefit period) | $1,676 |
| Medigap Plan G premium (age 65, avg) | $120–$180/month |
| Part D benchmark premium (avg) | ~$40/month |
| MA in-network OOP maximum (2026 average) | ~$5,000–$9,350 |
Note on Part B: The $185 monthly premium applies to everyone — whether you're in Medicare Advantage or Original Medicare. MA plans do not eliminate Part B costs; they layer on top of (or in some cases subsidize) that baseline.
Side-by-Side: Three Coverage Structures
Here's the annual cost architecture for each approach, before we model actual utilization:
| MA ($0 Premium) | Original Medicare Only | Original Medicare + Plan G + Part D | |
|---|---|---|---|
| Part B premium | $2,220 | $2,220 | $2,220 |
| Plan premium | $0 | $0 | $1,680 ($140/mo avg) + $480 ($40/mo Part D) |
| Part B deductible | Often covered | $257 | $257 (Plan G covers all else) |
| Copays / coinsurance | Variable (see below) | 20% of Medicare-approved costs | $0 after deductible (Plan G) |
| Annual floor cost | $2,220 | $2,477 | $4,637 |
| OOP exposure | Up to $9,350 | Unlimited | Near-zero after deductible |
On paper, Medicare Advantage looks dramatically cheaper — especially at $0 premium. But the floor cost comparison is almost meaningless. What matters is total cost under actual utilization.
The 10-Year Scenario: Light, Moderate, and Heavy Users
Scenario A: The Healthy 65-Year-Old (Low Utilization)
Annual healthcare use: 4 primary care visits, 1 specialist, no hospitalizations, 2 generic prescriptions.
MA ($0 premium, typical cost-sharing):
- 4 PCP visits × $10 = $40
- 1 specialist × $40 = $40
- 2 Rx × $10 = $20/month = $240/year
- Total annual: $2,540 | 10-year: $25,400
Original Medicare + Plan G + Part D:
- Part G premium: $1,680/year
- Part D premium: $480/year
- Part B deductible: $257
- Copays: $0 (Plan G covers 20% coinsurance)
- Total annual: $4,637 | 10-year: $46,370
Verdict for light users: MA wins by ~$20,970 over 10 years. If you're genuinely healthy and your MA plan's network includes your doctors, the math clearly favors MA at low utilization.
Scenario B: The Moderate User (1 Hospitalization, Ongoing Specialist Care)
Annual use: 1 inpatient stay (3 days), 6 specialist visits, 1 outpatient procedure, 4 maintenance prescriptions.
MA ($0 premium):
- Hospital stay (days 1–3): MA copay avg ~$350/day = $1,050
- 6 specialist visits × $50 = $300
- Outpatient procedure: 20% of $8,000 = $1,600
- 4 Rx (1 brand-name at Tier 3): ~$1,200/year
- Total annual: $6,370 | 10-year: $63,700
Original Medicare + Plan G + Part D:
- All premiums: $4,637
- Hospital stay: $0 (Plan G covers Part A coinsurance after deductible year 1)
- Specialist visits: $0
- Outpatient procedure: $0 (Plan G)
- 4 Rx via Part D: ~$600/year (same drugs, but Part D formulary may differ)
- Total annual: $5,237 | 10-year: $52,370
Verdict for moderate users: Plan G pulls ahead by ~$11,330 over 10 years. One hospitalization per year is enough to flip the math.
This is the kind of analysis Toravine runs for you — modeling your specific drug regimen, your historical utilization, and your local plan options so you're not doing this on a napkin before March 31.
Scenario C: The High-Utilizer (Chronic Condition, Multiple Specialists)
Annual use: 2 inpatient stays, 12 specialist visits, 1 surgery, multiple brand-name prescriptions.
MA ($0 premium, assuming you hit the OOP max):
- In-network OOP max: $9,350
- Part B premium: $2,220
- Total annual: $11,570 | 10-year: $115,700
Original Medicare + Plan G + Part D:
- All premiums: $4,637
- Medical cost-sharing: ~$257 (Part B deductible only)
- Part D OOP: up to $2,000 (2025 IRA cap now in effect)
- Total annual: ~$6,894 | 10-year: $68,940
Verdict for high utilizers: Plan G wins by ~$46,760 over 10 years. The OOP maximum on MA is not a ceiling that protects you — it's the realistic worst-case you're budgeting toward each year.
The IRMAA Variable: How Your Income Changes These Numbers
If your modified adjusted gross income (MAGI) from two years prior exceeds $106,000 (individual) or $212,000 (married filing jointly), you pay Income-Related Monthly Adjustment Amount (IRMAA) surcharges on top of your standard Part B and Part D premiums. These are not optional and they apply whether you're in MA or Original Medicare.
| Income (Individual, 2024 MAGI) | Part B Total/Month | Part D Surcharge/Month | Annual Extra vs Standard |
|---|---|---|---|
| ≤$106,000 | $185.00 | $0 | $0 |
| $106,001–$133,000 | $259.00 | $12.90 | +$887/year |
| $133,001–$167,000 | $370.00 | $33.30 | +$2,796/year |
| $167,001–$200,000 | $480.90 | $53.80 | +$4,750/year |
| $200,001–$500,000 | $591.90 | $74.20 | +$6,731/year |
Worked IRMAA example: A retired couple with $220,000 combined MAGI (2024) pays an extra $2,796/year each — totaling $5,592/year in additional Medicare premiums before a single claim is filed. Over 10 years, that's $55,920 in IRMAA surcharges that most people never anticipate in their retirement income planning.
If your income is near an IRMAA threshold, a Roth conversion, capital gain harvest, or QCD strategy in the right year can potentially keep you in a lower bracket. The Social Security Administration sets IRMAA using your MAGI from two years prior — which means income decisions in 2026 affect your 2028 Medicare premiums.
You can model your IRMAA exposure for various income scenarios at Toravine — including how a one-time income event like a home sale or Roth conversion moves you across brackets.
The Medigap Trap: Why March 31 Isn't Your Only Deadline
Here's the irreversible decision that the MA OEP deadline obscures. If you decide to leave Medicare Advantage and switch to Original Medicare after your initial Medigap open enrollment window (the 6 months starting when you're first enrolled in Part B), you may not be guaranteed the right to buy a Medigap policy at standard rates — or at all.
In most states, insurers can use medical underwriting outside of guaranteed issue periods. That means:
- A 70-year-old with diabetes, hypertension, or a prior cardiac event may be denied Medigap coverage
- Or offered coverage at significantly higher premiums
The window when you cannot be turned down is during your initial enrollment period. After that, you're subject to the rules of your state — and most states don't offer continuous guaranteed issue.
This is why switching from MA back to Original Medicare mid-career on Medicare can be a one-way door. You can always go from Medigap to MA. Going the other direction requires luck (good health) or living in one of the handful of states with broader protections (CT, ME, MA, NY are more protective; check your state's rules).
The post Medicare Advantage Open Enrollment Ends March 31: One Switch Allowed, But the Medigap Trap Could Cost You $3,000 a Year breaks this down further if you're weighing a switch right now.
What Rising Premium Pressure Means for Your Plan Comparison
The broader insurance market is also relevant context. A recent KFF poll found that many Americans are paying higher premiums and attribute rising costs to recent policy shifts. Meanwhile, the Medicare Rights Center submitted comments in March 2026 opposing proposed CMS rule changes that could limit access to affordable coverage — including provisions that could affect both ACA and Medicare-adjacent populations.
Why mention this for Medicare cost planning? Because Medicare Advantage premiums and benefit structures are not static. Plans that offer $0 premiums in 2026 do so because CMS payments to insurers support those benefits. If federal payment formulas tighten — as proposals periodically suggest — MA plan benefits can be cut mid-contract year or significantly reduced at renewal. A plan that covers your $400/month drug at Tier 2 today can move it to Tier 4 in January.
Original Medicare's cost structure is more predictable: Part B premiums are set annually and publicly announced, IRMAA brackets are indexed, and Plan G covers a defined set of benefits that don't change based on insurer profitability.
This is not a reason to panic or make a reactive switch. But it is a reason to build your plan comparison on the realistic range of future costs, not just today's premium.
Your Pre-March 31 Checklist
Before the MA OEP deadline closes, work through these:
- Pull your actual 2025 healthcare costs — total premiums paid, total cost-sharing paid, total drug costs
- Check your MA plan's 2026 OOP maximum (in-network vs. out-of-network are often very different numbers)
- Verify your doctors and preferred hospital are still in-network — networks change January 1
- Run your drug list through the current formulary — not last year's, the current one
- Check your 2024 MAGI against IRMAA thresholds to confirm your 2026 Part B premium bracket
- If considering dropping MA for Original Medicare, consult a SHIP counselor about Medigap underwriting rules in your state before you disenroll
The Bottom Line
A $0-premium Medicare Advantage plan is cheaper than Medigap Plan G if you're healthy and rarely use your coverage. It's more expensive — often significantly — if you experience a hospitalization, ongoing specialist care, or a major procedure. The crossover point is roughly one average inpatient stay per year.
IRMAA surcharges are additive to any plan structure and can add thousands per year at incomes above $106,000. And the Medigap underwriting risk means the decision to leave MA is not as reversible as joining it.
March 31 is a deadline, but not the only one that matters. The more important deadline is your initial Medicare enrollment window — which is when your Medigap options are fully open and your plan decision carries the least long-term risk.
Run your numbers before you decide, not after. Toravine is built specifically to model these comparisons with your actual plan options, your drug regimen, and your income — so the decision you make before March 31 is based on your math, not the industry average.
Sources
- Many ACA Customers Are Paying Higher Premiums. Most Blame Trump and Republicans, Poll Finds. — KFF Medicare
- Proposed Rule Could Undermine ACA Coverage — Medicare Rights Center
- The Annual Deadline to Make Certain Medicare Advantage Changes Is Fast Approaching — Medicare Rights Center
- In the Affordability Alphabet Soup of the ACA and EHBs, a Link to Higher Premiums Isn’t Clear-Cut — KFF Medicare
- What the Health? From KFF Health News: RFK Jr.’s Vaccine Schedule Changes Blocked — For Now — KFF Medicare