MAGI for Expats: Why Modified Adjusted Gross Income Matters for Credits and Surtaxes

2026-07-09

Last reviewed: July 9, 2026. This article reflects current IRS rules and EA exam requirements as of this date.

Modified Adjusted Gross Income (MAGI) is the starting point for determining eligibility for tax credits, surtaxes, and phaseouts. For expats, the interaction between the FEIE and MAGI is often misunderstood.

AGI vs MAGI

Your Adjusted Gross Income is the bottom line on the first page of your Form 1040. If you claim the FEIE, your excluded foreign income is subtracted before AGI. If you earn $120,000 and exclude the full $130,000 FEIE limit, your AGI is near zero (assuming no other income).

Modified Adjusted Gross Income takes your AGI and adds back certain deductions and exclusions. Which items are added back depends on what the MAGI is being used for. There is no single MAGI — there are multiple MAGI calculations for different purposes.

MAGI for the Net Investment Income Tax (NIIT)

For the NIIT, MAGI is your AGI with no add-back of the FEIE. However, the NIIT applies to net investment income, not earned income. The FEIE excludes earned income but not investment income. If you have $30,000 of interest and dividends and $200,000 of wages excluded by the FEIE, your AGI is $30,000 — below the NIIT threshold. No NIIT applies. But you still pay tax on the $30,000 of investment income.

MAGI for the Premium Tax Credit (ACA)

For ACA subsidies, MAGI includes the FEIE-excluded amount — it's added back. This prevents expats from claiming the FEIE to show artificially low income and qualify for subsidized health insurance they don't need (since they're abroad and not using US healthcare). If you earn $100,000 and exclude it with the FEIE, your MAGI for ACA purposes is $100,000 — well above the 400% FPL threshold, making you ineligible for subsidies.

MAGI for the Child Tax Credit

The Child Tax Credit ($2,000 per qualifying child) begins phasing out at $200,000 (single) / $400,000 (joint) of MAGI. For the CTC phaseout, the FEIE-excluded amount is not added back. An expat earning $250,000 who excludes $130,000 via the FEIE has an MAGI of $120,000 — well below the phaseout threshold. The Additional Child Tax Credit (refundable portion, up to $1,700 per child) uses earned income for its calculation, and FEIE-excluded earned income doesn't count.

MAGI for IRA Deduction Phaseout

For determining whether your traditional IRA contribution is deductible, the FEIE-excluded amount is added back to MAGI. This is designed to prevent high-earning expats from claiming they have low income for IRA purposes. An expat earning $150,000 (all excluded by the FEIE) has an MAGI of $150,000 for IRA purposes — above the phaseout range, making the IRA contribution non-deductible.

The Practical Takeaway

The FEIE makes your AGI look lower than your actual economic income
Some MAGI calculations add the FEIE back (ACA, IRA deduction) — these were designed to prevent gaming
Some don't (NIIT, CTC phaseout) — these create legitimate tax benefits for expats
You can't know which MAGI applies without checking the specific Code section for the benefit you're claiming

An EA who understands these interactions can optimize your elections: sometimes taking the FTC instead of the FEIE produces a better overall result because the higher AGI doesn't trigger adverse MAGI consequences, while the FTC eliminates the dual tax burden.

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