Is MAGI the Same as Taxable Income? What High Earners Should Know

By Kevin Luu, Co-Founder and Chief Learning Officer. Reviewed on 2026-09-30.

No. MAGI (modified adjusted gross income) is not the same as taxable income. MAGI starts from your adjusted gross income (AGI) and adds back (or, for some rules, removes) a few specific items, while taxable income is AGI minus your standard or itemized deductions. For a high-earning W-2 household, MAGI is almost always the larger number, and it is the one that decides whether you lose the Child Tax Credit, owe the 3.8% Net Investment Income Tax, or can contribute to a Roth IRA directly.

Taxable income sets your bracket. MAGI sets your eligibility. Mixing them up is how a family earning $900,000 ends up surprised by a tax bill or an excess Roth contribution.

AGI vs MAGI vs taxable income: the three numbers on one return

All three come from the same Form 1040, in this order:

1. Gross income. Wages (Form W-2, box 1), RSU income at vest, interest, dividends, capital gains and other income.
2. AGI. Gross income minus “above-the-line” adjustments from Schedule 1, such as a deductible HSA contribution made outside payroll or student loan interest. AGI is line 11a on the 2025 Form 1040.
3. MAGI. AGI with certain items added back or removed. There is no single MAGI. Each tax rule writes its own definition.
4. Taxable income. AGI minus the standard deduction or itemized deductions (line 15). This is the figure the brackets apply to.

The key point for a family at this income: deductions taken after AGI (the standard deduction, mortgage interest, the capped SALT deduction, charitable gifts) lower taxable income but do nothing to MAGI. Pay that never reaches box 1 of your W-2 (pre-tax 401(k) deferrals, payroll HSA contributions, a dependent care FSA, pre-tax health premiums) lowers AGI, and with it every version of MAGI.

Which MAGI applies to which rule

For most US-based W-2 families with no foreign income, several MAGI definitions collapse back to AGI. The differences show up in a few places.

One useful wrinkle: municipal bond interest is excluded from AGI and is not net investment income, so it does not raise your NIIT exposure. Some other definitions, such as the one used for marketplace health insurance subsidies, do add tax-exempt interest back. Always check which rule you are testing.

Worked example: a $950,000 Bay Area household in 2026

Assumptions (illustrative, not a recommendation): married filing jointly, two children ages 4 and 7, both parents W-2 employees in California. Total pay is $950,000 including RSU vests. Each spouse defers $24,500 pre-tax to a 401(k). They put the family maximum of $8,750 in an HSA through payroll, $7,500 in a dependent care FSA, and $6,000 in pre-tax health premiums. Outside of work they earn $25,000 of interest and dividends and realize $40,000 of long-term gains selling vested company shares. They rent, so they take the standard deduction.

What MAGI decides here:

• NIIT. MAGI exceeds $250,000 by $693,750, far more than their $65,000 of investment income, so the 3.8% applies to the full $65,000: about $2,470.
• Child Tax Credit. MAGI is $543,750 over the $400,000 threshold. The credit drops by $50 per $1,000, a $27,200 reduction, which wipes out the $4,400 for two children. The credit is gone above $488,000 for a two-child family.
• SALT cap. MAGI is above about $606,333, so the cap is the $10,000 floor, not $40,400. That is one reason this family’s itemized deductions do not beat the standard deduction.
• Roth IRA. MAGI is well above $252,000, so direct Roth IRA contributions are not allowed. Many families at this level use a backdoor Roth instead (a nondeductible traditional IRA contribution converted to Roth). That route is open because neither nondeductible traditional IRA contributions nor Roth conversions are tested against MAGI, and conversion income is left out of Roth MAGI (Pub 590-A). Any pre-tax money already sitting in traditional IRAs can make part of the conversion taxable.

Notice what did not move MAGI: the $32,200 standard deduction. Had they given $50,000 to a donor-advised fund, their taxable income could fall, but every MAGI test above would come out the same.

How California and Washington change the picture

California starts from federal AGI but adjusts it on Schedule CA. California does not conform to the federal HSA deduction, and employer HSA contributions reported on the W-2 (box 12, code W) are added back to California income (FTB Schedule CA (540) instructions, 2025). In the example, the $8,750 HSA contribution lowers federal AGI but not California AGI. California also taxes capital gains as ordinary income and does not follow the 2025 federal SALT cap changes. Wages also carry 1.3% SDI for 2026 with no wage cap, which is based on wages, not MAGI.

Washington has no tax on wage income for 2026. Its 7% capital gains tax (9.9% on gains above $1,000,000) is measured on Washington long-term capital gains after a standard deduction ($278,000 for 2025, the latest published), not on MAGI. That changes in 2028: Washington’s new 9.9% income tax applies to individuals and joint filers with AGI over $1,000,000 (WA DOR). For a Seattle-area family near $1M, keeping AGI down through pre-tax deferrals may start to matter for state tax too. Details of the income definition are still pending from the Department of Revenue.

What actually lowers MAGI for a W-2 family

• Pre-tax 401(k) or 403(b) deferrals, up to $24,500 each for 2026. After-tax mega backdoor Roth contributions do not lower MAGI.
• Payroll HSA contributions ($8,750 family limit for 2026, with a high-deductible plan), federal only.
• Dependent care FSA, up to $7,500 per household for 2026 if your employer’s plan has adopted the higher limit.
• Timing of gains. Selling vested RSU shares or rebalancing a taxable account adds gains to AGI. Spreading sales across years or harvesting losses can keep MAGI steadier.

At $750,000 to $3 million of income, these levers rarely bring MAGI back under a threshold like $400,000 or $250,000. Their value is in the tax saved on the deferred dollars, not in regaining a credit. The honest planning question is usually which thresholds you are already past for good, so you stop chasing them, and which ones (a Roth strategy, Washington’s 2028 line, a year with a large RSU vest) are still in play.

Common mistakes we see

• Checking Roth eligibility against taxable income. A family with $260,000 of AGI might have taxable income under $230,000 and assume they qualify. They do not: Roth eligibility uses MAGI, and an excess contribution carries a 6% excise tax for each year it stays in the account (Pub 590-A).
• Assuming charitable gifts reduce NIIT. Itemized deductions sit below AGI, so they never touch NIIT MAGI.
• Forgetting the RSU vest. RSU income is W-2 wages at vest and counts in AGI even though 22% (or 37% above $1 million of supplemental wages) was withheld. Withholding is not the same as tax owed.
• Using the federal number for California. HSA contributions and some other items make California AGI higher than federal AGI.

What to write down for your kids

Children rarely see a tax return, but they do see the outcomes: the extra 401(k) money, the shares sold in a down year, the account they cannot open. A short note in your family records explaining why you defer pre-tax, why you use a backdoor Roth, and why you stopped worrying about the Child Tax Credit gives them your reasoning, not just your results. As Kevin Luu puts it: “Your kids don’t need to inherit your portfolio. They need to inherit your decision-making process.” Families who use the FamilyKnowledge® System keep these short notes in one place.

Frequently asked questions

Is MAGI higher or lower than taxable income?

For nearly every W-2 family, MAGI is higher. Taxable income subtracts the standard or itemized deduction from AGI, while MAGI starts at AGI and usually adds items back. In our example, MAGI was $943,750 and taxable income was $911,550, a gap equal to the $32,200 standard deduction for 2026.

Does the standard deduction reduce MAGI?

No. The standard deduction comes after AGI, so it lowers taxable income but has no effect on MAGI. The same is true of itemized deductions such as mortgage interest, the SALT deduction and charitable gifts. We explain this in more detail in does the standard deduction reduce MAGI.

Where do I find MAGI on my Form 1040?

There is no MAGI line. You start with AGI (line 11a on the 2025 form) and apply the adjustments for the specific rule, such as Worksheet 2-1 in Publication 590-A for Roth IRAs or Form 8960 for NIIT. See which line is MAGI on Form 1040.

Next step

Pull last year’s return, find AGI, and list the thresholds you are above: NIIT, the Child Tax Credit, the SALT phase-down and the Roth IRA limit. That list tells you which decisions this year can still change the outcome. For more on lowering MAGI, read how to reduce modified adjusted gross income, or see how the Age Five Family Office™ handles tax management and retirement and employee benefits for families. If you want a second set of eyes on your own numbers, the Tax & Wealth Assessment is where we start.

This is general education. The right move depends on your family’s full picture.

Written by

Kevin Luu

Co-Founder and Chief Learning Officer, Bright Advisers

Kevin has advised high-income W-2 tech and biotech families since 2015, and leads the education-first Age Five Family Office from Brea, California.

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