Reference · Pub 590-A · Form 8962 · IRC §1411
MAGI Isn't One Number: The Seven Definitions That Decide Your Taxes
Seven programs, seven different MAGIs — here's the one table that keeps them straight. Every row starts from AGI on Form 1040 line 11, then adds back a different set of items.
The comparison table
| Program | Muni interest | Nontaxable SS | FEIE | §135 bonds | §137 adoption | PR / Am. Samoa | IRA deduction | Student loan int. | − Roth conv | Lookback | Calc |
|---|---|---|---|---|---|---|---|---|---|---|---|
| IRMAA (Medicare Part B & D surcharges) | Yes | No | Yes | Yes | No | Yes | No | No | No | 2 yr | Open → |
| Roth IRA contribution eligibility | No | No | Yes | Yes | Yes | No | Yes | Yes | Yes | current | Open → |
| ACA Premium Tax Credit (household MAGI) | Yes | Yes | Yes | No | No | No | No | No | No | current | Open → |
| Education credits (AOTC and LLC) | No | No | Yes | No | No | Yes | No | No | No | current | Open → |
| Net Investment Income Tax (§1411) | No | No | Yes | No | No | No | No | No | No | current | Open → |
| Traditional IRA deduction (active participant) | No | No | Yes | Yes | Yes | No | Yes | Yes | No | current | Open → |
| Student-loan interest deduction (§221) | No | No | Yes | No | No | Yes | No | Yes | No | current | Open → |
✓ = the item is added back to AGI for that MAGI. Blank = not added back. Scroll horizontally on mobile.
The OBBB deductions do NOT lower any MAGI on this page.
The tips deduction, overtime deduction, car-loan interest deduction, and senior deduction from P.L. 119-21 (OBBB) are below-the-line: they reduce taxable income, but they do not reduce AGI. Every MAGI on this page starts from AGI — so they can't help you qualify for a Roth contribution, an ACA subsidy, an education credit, or a lower IRMAA bracket. OBBB deduction hub →
Program by program
IRMAA (Medicare Part B & D surcharges)
AGI + tax-exempt interest + FEIE + §135 bond interest + Puerto Rico / American Samoa exclusions, from the return two years back (2026 premiums come off your 2024 return). Nontaxable Social Security is not added.
Open calculatorRoth IRA contribution eligibility
AGI + any traditional IRA deduction + the student loan interest deduction + FEIE + §135 bond interest + §137 adoption benefits — then SUBTRACT income from Roth CONVERSIONS. Conversions can push you into a high tax bracket but never into a lower Roth contribution.
Open calculatorACA Premium Tax Credit (household MAGI)
AGI + tax-exempt interest + the NONTAXABLE portion of Social Security + FEIE. Household MAGI adds every dependent required to file. The only MAGI that counts nontaxable SS.
Open calculatorEducation credits (AOTC and LLC)
AGI + FEIE + Puerto Rico / U.S. territory exclusions. Does NOT add back tax-exempt interest or nontaxable Social Security.
Open calculatorNet Investment Income Tax (§1411)
AGI plus the net FEIE addback. The 3.8% surtax applies on the lesser of net investment income or the amount by which this MAGI exceeds $200k single / $250k joint (thresholds not indexed).
Open calculatorTraditional IRA deduction (active participant)
Same addback family as Roth-IRA MAGI (the IRA deduction itself and the student loan interest deduction are added back), but conversions are NOT subtracted here. Governs whether an active participant's deduction phases out.
Open calculatorStudent-loan interest deduction (§221)
AGI figured before the student-loan-interest deduction, plus FEIE/housing and excluded Puerto Rico / American Samoa income. The traditional IRA deduction, §135 bond interest and §137 adoption benefits stay excluded. Not available on MFS.
Open calculatorLevers that move MAGI — and levers that don't
Lowers AGI, and every MAGI unless noted
- Pre-tax 401(k) / 403(b) / 457(b) contributions
- HSA contributions — HSA calculator
- Qualified charitable distributions at 70½+ — QCD guide
- Traditional IRA deduction (if eligible) — lowers AGI and most MAGIs, but the two IRA MAGIs add it back
- Harvesting capital losses against gains
Doesn't move MAGI
- OBBB tips, overtime, car-loan, senior deductions (below-the-line)
- Standard deduction and itemized deductions
- QBI (§199A) deduction
- Tax credits (they cut tax, not AGI)
Raises MAGI
- Taxable Roth conversions — they raise AGI, so they raise IRMAA (two years later), ACA, NIIT, education-credit and IRA-deduction MAGI. Only Roth-contribution MAGI subtracts them back out. A $50,000 taxable conversion takes IRMAA MAGI from $100,000 to $150,000.
Frequently asked questions
Is MAGI the same as AGI?
No — and MAGI is not one number. Every program (IRMAA, ACA, Roth IRA, education credits, NIIT, IRA deduction, student-loan interest) starts from AGI on Form 1040 line 11, then adds back a DIFFERENT set of items. The seven combinations differ, so a taxpayer can be above one MAGI phase-out and below another at the same income.
Does tax-exempt interest count for Medicare (IRMAA)?
Yes. IRMAA MAGI is AGI + tax-exempt interest (Form 1040 line 2a), plus any excluded foreign earned income, §135 savings-bond interest and Puerto Rico / American Samoa income (42 U.S.C. §1395r(i)(4)(A)), and it uses a return two years old — your 2026 Part B and Part D premiums are set from your 2024 MAGI. Municipal-bond interest that escapes federal income tax still shows up in this MAGI.
Do Roth conversions count against Roth contribution limits?
No. The Roth-IRA-contribution MAGI is the one place where conversion income is SUBTRACTED after the addbacks. A large Roth conversion can push you into a higher bracket, but it can never phase you out of a direct Roth contribution.
Do the new OBBB deductions (tips, overtime, car loan, senior) lower my MAGI?
Never. The OBBB deductions are below-the-line: they reduce taxable income, but they do NOT reduce AGI, and every MAGI on this page starts from AGI. That means they do not help you qualify for a Roth contribution, the ACA subsidy, education credits, the traditional-IRA deduction, or a lower IRMAA bracket.
Sources & References
Primary references used for this content
Contributions to IRAs
IRA contribution limits, deductibility, and phase-outs
View on irs.gov
Premium Tax Credit (PTC)
Household MAGI worksheet for the ACA premium tax credit
View on irs.gov
Imposition of tax (Net Investment Income Tax)
3.8% NIIT and its MAGI-based threshold
View on law.cornell.edu
Medicare premiums: rules for higher-income beneficiaries
Official IRMAA definition and the two-year lookback
View on ssa.gov
✓4 primary sources; links re-checked on a weekly rotation by the source watcher
Disclaimer: This calculator provides estimates for educational purposes only. Not tax, legal, or financial advice. Results may vary based on your specific circumstances. Consult a qualified CPA or tax professional for personalized guidance.