Modified AGI (MAGI) Calculator 2026 — Multi-Purpose

Calculate your 2026 Adjusted Gross Income (Form 1040 line 11) and the four most-cited Modified AGI variants — IRA MAGI (Roth contribution limits), ACA MAGI (premium tax credit), Medicare IRMAA MAGI (Part B/D surcharge tier), and Net Investment Income Tax MAGI (3.8% surcharge). Each MAGI uses different add-backs. Free, private, runs in your browser.

Filing & Gross Income

Filing status

Total gross income (USD) Wages, business, capital gains, dividends, interest — before any deductions.

Above-the-Line (Adjustments — reduce AGI)

HSA contribution ($) Above-line. 2026 cap: $4,400 self / $8,750 family + $1,000 catch-up if 55+.

Traditional IRA deduction ($) Above-line if eligible. 2026 cap: $7,000 / $8,000 if 50+.

Student loan interest ($) Above-line, max $2,500 with phase-out.

Half SE tax + SE health ins + SE retirement ($) Combined: 50% of SE tax + SE health insurance + SEP/Solo 401(k) above-line.

Other above-line adjustments ($) Educator expenses, alimony pre-2019, jury duty pay returned, etc.

MAGI Add-Backs (vary by purpose)

Foreign earned income exclusion (Form 2555) ($) Added back for IRA, ACA, IRMAA, NIIT MAGI calculations.

Foreign housing exclusion / deduction ($) Added back for IRA, ACA, IRMAA MAGI.

Tax-exempt interest (line 2a) ($) Municipal bond interest — added back for ACA, IRMAA, NIIT MAGI.

Untaxed Social Security benefits ($) SS portion not already in AGI — added back for ACA MAGI only.

Excludable savings bond interest (Form 8815) ($) Added back for IRA MAGI.

Employer adoption benefits exclusion ($) Added back for IRA MAGI (Roth limit calc).

Adjusted Gross Income (Line 11)

Taxable income source

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IRA MAGI (Roth limit)

ACA MAGI (Premium Tax Credit)

Medicare IRMAA MAGI

NIIT MAGI (3.8% surtax)

Threshold Position (2026)

Purpose	Your MAGI	2026 threshold	Status

MAGI Add-Back Detail

Step	Amount

2026 thresholds (estimated, indexed for inflation): Roth IRA single phase-out ~$153,000-$168,000; MFJ ~$240,000-$250,000 — verify with IRS Rev. Proc. 2025-19. NIIT thresholds $200,000 single / $250,000 MFJ (statutory, not indexed). Medicare IRMAA Part B 2026 first surcharge tier estimated above $109,000 single / $218,000 MFJ — verify with CMS. ACA Premium Tax Credit phase-out by household size (FPL 100%-400%). Different calculations have different add-backs — this calculator follows IRS Form 1040 + Pub 590-A, IRC § 36B, and § 1411.

Source: IRS Form 1040 + Publication 590-A (IRA) + 26 USC § 36B (ACA PTC) + § 1411 (NIIT). Last updated: May 3, 2026.

What Is MAGI (Modified Adjusted Gross Income)?

Modified Adjusted Gross Income (MAGI) is your Adjusted Gross Income (Form 1040 line 11) with specific items added back depending on the tax provision being applied. There is no single MAGI — there are at least four common variants in 2026, each defined by its own statute. The IRA MAGI determines Roth contribution and traditional IRA deduction limits; the ACA MAGI determines Premium Tax Credit eligibility on the Marketplace; the Medicare IRMAA MAGI sets your Part B and Part D premium surcharge tier two years after; and the Net Investment Income Tax (NIIT) MAGI determines the 3.8% surtax on investment income above $200,000 single or $250,000 MFJ. Source: IRS Publication 590-A.

Because each MAGI uses different add-backs, the same gross income can produce four different MAGIs — and trigger different penalties or credit reductions. This tool computes all four side by side using your single set of inputs.

IRA MAGI vs ACA MAGI vs IRMAA MAGI vs NIIT MAGI

The four variants share AGI as a base but diverge on add-backs:

IRA MAGI (Pub 590-A): AGI + traditional IRA deduction + student loan interest + foreign earned income/housing exclusions + savings bond interest exclusion + employer adoption benefits exclusion. Used for Roth contribution and traditional IRA deduction phase-outs.
ACA MAGI (IRC § 36B): AGI + tax-exempt interest + untaxed Social Security benefits + foreign earned income/housing exclusions. Used for Premium Tax Credit and cost-sharing reduction eligibility on Healthcare.gov.
Medicare IRMAA MAGI (42 USC § 1395r): AGI + tax-exempt interest. Used by SSA two years later (2026 returns affect 2028 Medicare premiums) for Part B and Part D surcharges.
NIIT MAGI (IRC § 1411): AGI + foreign earned income/housing exclusions. Used to determine the 3.8% surtax on net investment income above the threshold.

Common Threshold Cliffs to Watch in 2026

MAGI cliffs in 2026 are sharper than most taxpayers expect. The Roth IRA phase-out for single filers begins around $153,000 and ends around $168,000 (MFJ approximately $240,000-$250,000) — final 2026 figures are set by IRS Revenue Procedure 2025-19. The Net Investment Income Tax cliff is fixed by statute at $200,000 single / $250,000 MFJ — it has never been indexed since enactment in 2013, so more taxpayers cross it every year. The Medicare IRMAA Part B cliff for 2026 is estimated above $109,000 single / $218,000 MFJ — and IRMAA is a true cliff (not phased), so $1 over the threshold can add $80+ per month to Part B alone, plus a Part D surcharge.

How to Use This Calculator for Tax Planning

Three high-leverage moves to lower your MAGI before the 2026 deadlines: (1) max your HSA — every dollar reduces AGI 1:1 with no add-back to most MAGI variants; (2) max your traditional 401(k) at work — pre-tax 401(k) contributions reduce AGI but do not add back to IRA, ACA, or NIIT MAGI; (3) tax-loss harvest before December 31 — capital losses up to $3,000 reduce AGI and all four MAGIs simultaneously. Roth conversions increase MAGI in the year of conversion — model the IRMAA two-year lookback before converting in retirement. Last updated: May 3, 2026.

Frequently Asked Questions

What is Modified Adjusted Gross Income (MAGI)?

MAGI is your Adjusted Gross Income (Form 1040 line 11) with specific items added back depending on the tax provision being applied. There is no single MAGI — there are at least four common variants in 2026, each defined by its own statute: IRA MAGI (Pub 590-A), ACA MAGI (IRC § 36B), Medicare IRMAA MAGI, and Net Investment Income Tax MAGI (IRC § 1411).

Why are there four different MAGI calculations?

Each tax provision Congress wrote uses a different definition of MAGI to capture the specific income types it cares about. The IRA MAGI adds back the traditional IRA deduction itself (so the deduction does not enable a higher Roth contribution). The ACA MAGI adds back tax-exempt interest because Marketplace subsidies should reflect the same income visibility as means-tested programs. The IRMAA and NIIT MAGIs use narrower add-backs reflecting their different policy goals.

What are the 2026 Roth IRA MAGI limits?

For 2026, the Roth IRA contribution phase-out is estimated at $153,000-$168,000 for single and head of household filers, $240,000-$250,000 for married filing jointly, and $0-$10,000 for married filing separately (very restrictive). Final 2026 numbers are set by IRS Revenue Procedure 2025-19. Above the phase-out end, no direct Roth contribution is permitted (backdoor Roth conversion remains available).

What is the NIIT 3.8% surtax threshold?

The Net Investment Income Tax (NIIT) under IRC § 1411 applies a 3.8% surtax on the lesser of net investment income or MAGI above $200,000 (single/HOH), $250,000 (MFJ), or $125,000 (MFS). These thresholds are set by statute and have not been adjusted for inflation since 2013, so more taxpayers cross the threshold every year as wages and asset prices rise.

How does Medicare IRMAA use my MAGI?

The Social Security Administration uses your IRMAA MAGI from your tax return two years prior to set Medicare Part B and Part D premium surcharges. Your 2026 IRMAA MAGI determines your 2028 Medicare premiums. IRMAA is a true cliff (not phased) — $1 over a tier threshold can add $80+ per month to Part B alone, plus a Part D surcharge.

Can I lower my MAGI before year end?

Yes — three high-leverage moves: (1) max your HSA, which reduces AGI 1:1 with no add-back to most MAGI variants; (2) max your traditional 401(k) at work — pre-tax 401(k) contributions reduce AGI and do not add back to IRA, ACA, or NIIT MAGI; (3) tax-loss harvest before December 31 — capital losses up to $3,000 per year reduce AGI and all four MAGIs simultaneously. Roth conversions increase MAGI in the year of conversion.