MAGI Calculator for Medicare — Find Your 2026 Modified Adjusted Gross Income for IRMAA Surcharge Brackets
Figures last verified against SSA.gov, IRS.gov, and Medicare.gov in July 2026.
Quick Answer
Your Medicare MAGI is your Adjusted Gross Income (IRS Form 1040 Line 11) plus tax-exempt interest (Line 2a) plus any foreign income exclusions. In 2026, IRMAA surcharges begin at $109,000 for single filers and $218,000 for joint filers. Social Security uses your 2024 tax return to set 2026 Medicare premiums — meaning retirees often pay surcharges based on income they no longer earn.
Most Medicare beneficiaries assume their regular AGI is the number Social Security uses to set their premium tier. It isn't. Medicare uses a specially defined MAGI that adds back income sources like municipal bond interest that never appear in your regular taxable income — which is why thousands of retirees are surprised by IRMAA surcharges they didn't anticipate. This free calculator shows you the exact figure SSA uses, broken down by component, so you can verify your tier or plan to stay under it.
- Retirees with income above $95,000 (single) or $190,000 (joint) who want to check whether they're close to an IRMAA threshold before SSA sends a determination letter.
- Seniors planning a large IRA withdrawal, Roth IRA conversion, or capital gain event who want to model the IRMAA premium impact before executing the transaction.
- Medicare beneficiaries who received an IRMAA surcharge notice and want to independently verify the income bracket SSA used — the first step before deciding whether to file a Form SSA-44 appeal.
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Your MAGI calculation shows which Medicare bracket you are in. This optional workbook helps you understand how income decisions — like Roth conversions — affect that number.
How to Calculate Your Medicare MAGI — Step by Step
- Step 1 — Find your AGI on the correct tax return year. Social Security uses the tax return from two years prior. For 2026 Medicare premiums, SSA is using your 2024 IRS Form 1040. Pull that specific return and locate Line 11 — your Adjusted Gross Income. This is the starting point for your Medicare MAGI. If you don't have the paper return, request a transcript at IRS.gov — Get Transcript.
- Step 2 — Find your tax-exempt interest on Form 1040 Line 2a. Near the top of Page 1, Line 2a shows tax-exempt interest income — most commonly from municipal bonds, municipal bond mutual funds, or tax-exempt money market funds. This amount does not appear in your AGI but Social Security is legally required to add it back to compute your Medicare MAGI. Even a small amount of muni bond interest can push you over an IRMAA bracket cliff.
- Step 3 — Add any foreign income exclusions (if applicable). If you excluded income under the Foreign Earned Income Exclusion (Form 2555), or received income from a U.S. territory (Puerto Rico, Guam, American Samoa, or Northern Mariana Islands) that was not included in your AGI, add those amounts. Most U.S. retirees have zero here, but it is worth checking.
- Step 4 — Enter your amounts and read your tier result. Enter your AGI, tax-exempt interest, and any foreign exclusion into the calculator above. Your Medicare MAGI total displays alongside your 2026 IRMAA tier, the monthly Part B surcharge, the monthly Part D surcharge, and your total combined monthly premium impact.
💡 Pro Tip
If your income dropped significantly in the past two years due to retirement, reduced work, divorce, or a spouse's death, you may qualify to have your IRMAA recalculated using your current lower income immediately — without waiting for a new tax year. Use our Should I Appeal My IRMAA? Wizard to check eligibility, then generate your SSA-44 cover letter at our IRMAA Appeal Letter Generator.
What Income Counts Toward Medicare MAGI — and What Doesn't
| Income Type | Where on Form 1040 | Counts Toward MAGI? |
|---|---|---|
| Pension / annuity income | Lines 5a–5b (taxable portion) | ✅ Yes — included in AGI |
| Traditional IRA / 401(k) withdrawals | Lines 4a–4b (taxable portion) | ✅ Yes — included in AGI |
| Taxable Social Security benefits | Line 6b | ✅ Yes — included in AGI |
| Wages, salaries | Line 1a | ✅ Yes — included in AGI |
| Capital gains (long-term & short-term) | Schedule D / Line 7 | ✅ Yes — included in AGI |
| Dividends (ordinary & qualified) | Lines 3a–3b | ✅ Yes — included in AGI |
| Tax-exempt municipal bond interest | Line 2a (not in AGI) | ✅ Yes — added back |
| Foreign earned income exclusion | Form 2555 (excluded from AGI) | ✅ Yes — added back |
| Qualified Roth IRA distributions | Not on Form 1040 (tax-free) | ❌ No — excluded from MAGI |
| Qualified Roth 401(k) withdrawals | Not on Form 1040 (tax-free) | ❌ No — excluded from MAGI |
| HSA distributions (medical expenses) | Not in AGI if qualified | ❌ No — excluded from MAGI |
| Non-taxable Social Security benefits | Line 6a minus 6b | ❌ No — excluded from MAGI |
| Life insurance proceeds / inheritances | Not reported (tax-free) | ❌ No — excluded from MAGI |
Source: Social Security Administration IRMAA regulations and IRS Form 1040 line-by-line instructions. Consult a CPA for complex situations involving foreign income, trust distributions, or non-qualified annuities.
⚠️ The Tax-Exempt Bond Surprise — Why "Tax-Free" Income Still Triggers IRMAA
Municipal bond interest is exempt from federal income tax and does not appear in your AGI. But Social Security is legally required to add it back (Form 1040 Line 2a) when calculating Medicare MAGI. This means holding $6,000 in muni bond interest while your AGI is $106,000 pushes your Medicare MAGI to $112,000 — above the 2026 single-filer Tier 1 threshold of $109,000 — triggering an extra $81.20/month on Part B premiums and $14.50/month on Part D, even though your taxable income was "only" $106,000.
Real-Life MAGI Calculation Examples — How the Numbers Work
Brenda is a single retiree. She carefully managed her IRA withdrawals to keep her AGI just under the IRMAA threshold — but her municipal bond portfolio generated tax-exempt interest she forgot to account for in her MAGI calculation.
| MAGI Component | Amount |
|---|---|
| AGI (Form 1040 Line 11) — pension + IRA withdrawals | $105,000 |
| Tax-exempt municipal bond interest (Line 2a) | + $6,500 |
| Foreign income exclusion | $0 |
| Medicare MAGI Total | $111,500 |
| 2026 Single-Filer Tier 1 Threshold | $109,000 |
| IRMAA Status | ⚠️ Tier 1 — $81.20/mo Part B + $13.70/mo Part D |
Planning Option: By shifting $6,500 from municipal bonds into a HYSA or Treasury bills (whose interest is taxable but already in her AGI), Brenda's MAGI drops to $105,000 — below the threshold. She pays slightly more in federal tax but eliminates the IRMAA surcharge entirely, for a net gain. Use our IRMAA Calculator to model the impact of different income scenarios on your specific tier.
Robert and Patricia file jointly. In 2024 they executed a $180,000 Roth IRA conversion to reduce future RMDs. Their regular AGI was $200,000 — combined with the conversion, their 2024 MAGI jumped to $380,000, placing them in IRMAA Tier 4 for 2026 premiums.
| MAGI Component | Amount |
|---|---|
| Base AGI (pensions + Social Security + dividends) | $200,000 |
| Roth IRA conversion (added to AGI) | + $180,000 |
| Tax-exempt interest (Line 2a) | $0 |
| 2024 Medicare MAGI | $380,000 |
| 2026 IRMAA Tier (joint) | Tier 4 ($340,000–$749,999 range) |
| Monthly IRMAA surcharge (combined Part B + D) | $744.70/month per person |
Planning Lesson: Phased Roth conversions — staying under IRMAA tier boundaries each year — can achieve the same long-term tax benefit without triggering a surcharge surge. Use our Roth Conversion Calculator alongside this MAGI tool to model annual conversion amounts that maximize Roth benefits while staying under IRMAA thresholds.
Diana converted her IRA to a Roth in phases between ages 63 and 67, keeping each year's conversion under the Tier 1 IRMAA threshold. Now at 72, her RMDs are eliminated and she draws $45,000/year tax-free from her Roth IRA — none of which counts toward Medicare MAGI.
| MAGI Component | Amount |
|---|---|
| Social Security benefits (taxable portion) | $28,000 |
| Pension income | $42,000 |
| Roth IRA distributions (qualified — MAGI-free) | $45,000 — does NOT count |
| Tax-exempt interest (Line 2a) | $0 |
| Medicare MAGI Total | $70,000 |
| IRMAA Status | ✅ Below $109,000 threshold — no surcharge |
Key Takeaway: The best time to plan IRMAA-friendly income is before Medicare enrollment — typically ages 60–64. Use our RMD Calculator by Age alongside this MAGI tool to model how your future Required Minimum Distributions will affect your MAGI once you turn 73.
These are illustrative examples using official 2026 IRMAA thresholds. Individual income situations vary significantly. Consult a CPA or tax professional for personalized Roth conversion and IRMAA planning advice before making large financial transactions.
Common Medicare MAGI Calculation Mistakes and How to Avoid Them
Using Your Current Year's Income Instead of the Two-Year-Old Return
The most common planning error is running your MAGI calculation using your current year's income when SSA is actually using your tax return from two years prior. If you retired in 2025 and are planning for 2026 Medicare premiums, SSA is using your 2024 return — not your 2025 one. Using the wrong year produces the wrong tier result and leads to poor planning decisions.
The fix is to always identify which tax year SSA is using for the coverage year you're planning for, then pull that specific return. For 2026 premiums: use 2024 return. For 2027: use 2025 return. If your income dropped dramatically in the more recent year due to retirement, you may be eligible to file a Form SSA-44 appeal immediately rather than waiting two years for your lower income to flow through to your premiums.
Forgetting to Add Back Tax-Exempt Municipal Bond Interest (Line 2a)
This is the single most common reason retirees cross an IRMAA threshold unexpectedly. Municipal bond interest feels invisible because it doesn't appear in taxable income or AGI. But SSA legally requires adding it back. Even $4,000 to $8,000 in muni interest can push a borderline-AGI retiree from no surcharge to Tier 1 IRMAA — triggering $81.20+/month in extra premiums.
The fix is to always check Form 1040 Line 2a before finalizing your MAGI estimate — even if you think you don't hold muni bonds. Muni bond interest can arrive through bond mutual funds and ETFs held inside a brokerage account, making it easy to overlook. Check your 1099-INT and 1099-DIV for Box 8 (tax-exempt interest) to capture all sources.
Assuming All Roth Distributions Are Always MAGI-Free
Qualified Roth IRA distributions — from accounts at least 5 years old where you are at least 59½ — are excluded from Medicare MAGI. But non-qualified Roth distributions (early withdrawals, or from accounts less than 5 years old) are included in income and count toward MAGI. Similarly, a Roth IRA conversion generates taxable income in the conversion year and increases your MAGI for the two following Medicare premium years.
The fix is to confirm your Roth account meets both the 5-year holding period and the age-59½ requirement before treating distributions as MAGI-exempt. If you're considering a Roth conversion, model the two-year IRMAA impact using this MAGI tool before executing it.
Not Checking MAGI Before Making Large Year-End Financial Decisions
IRMAA brackets operate as cliffs — being $1 above a threshold triggers the full tier surcharge ($81.20 to $444.90/month extra on Part B alone). Seniors who sell a home, take a large IRA withdrawal, or realize capital gains in December without first checking their MAGI can accidentally tip into a higher tier for the next two Medicare premium years.
The fix is to run this MAGI calculator in October or November before making any large year-end financial move. If you're close to a threshold, consider timing the transaction into the next calendar year, accelerating a charitable deduction using a Qualified Charitable Distribution (QCD) from your IRA, or spreading a large withdrawal across two years. The IRA & 401(k) Withdrawal Planner can help model withdrawal timing to stay under IRMAA cliffs.
Official Government Sources Used in This Tool
| Source Name | What We Used It For | Direct Link |
|---|---|---|
| Social Security Administration — IRMAA & MAGI Rules | Official definition of Medicare MAGI for IRMAA purposes, required income add-backs, and the two-year look-back rule used to set surcharge tiers | SSA.gov IRMAA Rules |
| Medicare.gov — 2026 Part B & Part D IRMAA Surcharge Tables | Current 2026 IRMAA income thresholds ($109k/$218k single/joint) and monthly Part B surcharge amounts for all five IRMAA tiers | Medicare.gov Part B Costs |
| IRS Form 1040 — AGI and Tax-Exempt Interest Line Definitions | Line 11 (AGI) and Line 2a (tax-exempt interest) definitions used as inputs for the Medicare MAGI formula | IRS Form 1040 Instructions |
| 20 CFR § 418.1110 — SSA Regulations on MAGI Calculation | Federal regulatory basis for Social Security's use of Modified Adjusted Gross Income to determine IRMAA brackets — specifically the required add-back of tax-exempt interest | 20 CFR Part 418 — eCFR |
Seniors Audit is an independent educational platform. We are not affiliated with, endorsed by, or connected to the Social Security Administration, IRS, CMS, or any government agency. All calculations use the official formulas and 2026 figures published by the agencies above.
Frequently Asked Questions: MAGI for Medicare
What is Medicare MAGI and how is it different from my regular AGI?
Medicare MAGI (Modified Adjusted Gross Income) is the income figure Social Security uses to determine your IRMAA surcharge bracket. It starts with your Adjusted Gross Income (Form 1040 Line 11) and adds back tax-exempt interest (Line 2a), foreign earned income exclusions (Form 2555), and tax-exempt U.S. territory income. Your regular AGI does not include these add-backs — which is why your Medicare MAGI can be higher than your federal taxable income, even if you felt you had a low-income year.
What income is included in the IRMAA calculation?
Your Medicare MAGI for IRMAA purposes includes everything in your AGI — wages, pension income, traditional IRA and 401(k) withdrawals, taxable Social Security benefits, interest, dividends, and capital gains — plus the required add-backs: tax-exempt interest from municipal bonds (Form 1040 Line 2a), any foreign earned income you excluded, and tax-exempt U.S. territory income. These add-backs are specifically required by Social Security regulations, not just IRS rules.
What income is NOT included in the Medicare MAGI calculation?
Income excluded from Medicare MAGI includes: qualified Roth IRA distributions (tax-free if the account is 5+ years old and you are 59½ or older), qualified Roth 401(k) withdrawals, Health Savings Account (HSA) distributions used for qualified medical expenses, life insurance proceeds, non-taxable gifts or inheritances, and the non-taxable portion of your Social Security benefits. Strategic Roth conversions done in prior years can meaningfully reduce future MAGI for IRMAA planning.
How does tax-exempt municipal bond interest push me into a higher IRMAA bracket?
Municipal bond interest is exempt from federal income tax and does not appear in your AGI — but Social Security specifically requires it to be added back when calculating your Medicare MAGI (Form 1040 Line 2a). This is one of the most common surprises that pushes retirees over an IRMAA threshold. For example, if your AGI is $106,000 and you hold $5,000 in muni bond interest, your Medicare MAGI is $111,000 — above the $109,000 Tier 1 threshold — and you pay an extra $81.20/month on Part B.
Which year's tax return does Social Security use to calculate my IRMAA?
Social Security uses your federal tax return from two years prior. For 2026 Medicare premiums, SSA uses your 2024 IRS Form 1040. For 2027 premiums, they will use your 2025 return. This two-year lag is exactly why newly retired seniors often pay IRMAA surcharges based on their final working-year salary — and why filing Form SSA-44 to appeal based on a life-changing event can eliminate that surcharge immediately rather than waiting two years.
How can I use this MAGI calculator for IRMAA tax planning?
Run this calculator before making large year-end financial decisions — IRA withdrawals, Roth conversions, municipal bond purchases, or capital gain realizations. If your current estimated MAGI is close to an IRMAA threshold ($109,000 single / $218,000 joint for Tier 1 in 2026), you can adjust your withdrawal amounts or time a charitable contribution to stay under the cliff. Even a $1 overage triggers the full IRMAA tier surcharge — precision planning with this tool can save $81 to $487/month.
Where do I find my AGI and tax-exempt interest on my Form 1040?
On IRS Form 1040, your Adjusted Gross Income (AGI) is on Line 11 — near the bottom of Page 1. Your tax-exempt interest income is on Line 2a — near the top of Page 1, in the Income section. Both are clearly labeled. If you use tax software, both figures appear on your federal return summary. If you filed with a tax professional, ask for a copy of your Form 1040 transcript from IRS.gov.
Does a Roth IRA conversion count toward my Medicare MAGI?
Yes — a Roth IRA conversion generates taxable income in the year of conversion, which is included in your AGI and therefore your Medicare MAGI. A large Roth conversion can push you into a higher IRMAA bracket for the two following premium years. However, once converted, future qualified Roth distributions are permanently excluded from Medicare MAGI. This trade-off is why strategic, phased Roth conversions done before Medicare enrollment — or timed to stay under IRMAA thresholds — can produce long-term premium savings.
About This Educational Estimate: This tool is for educational purposes only. Seniors Audit uses the official formulas published by Social Security Administration (SSA), but results are estimates based on the information you entered. Rules, rates, and eligibility thresholds change annually and vary by individual circumstance.
Always verify your specific result directly with Social Security Administration (SSA) at 1-800-772-1213 or at www.ssa.gov/benefits/medicare/irmaa.html before making enrollment, coverage, or financial decisions.
If you have Medicare questions, a free SHIP counselor in your state can review your specific situation at no cost — find yours at shiphelp.org.
Seniors Audit is independent and not affiliated with any government agency or insurance company. We are not affiliated with, endorsed by, or connected to any government agency, insurance company, or financial services firm. All calculations use the official formulas and current figures published by the agencies listed above. We do not receive payment for referrals, leads, or any action taken by visitors to this site. Last reviewed: July 2026.