Modified Adjusted Gross Income

🇺🇸 Modified Adjusted Gross Income (MAGI) is a calculation that starts with one's Adjusted Gross Income and then applies various modifications to that amount.

There are multiple versions of MAGI, and one should take care to use the applicable modifications.

MAGI for Affordable Care Act purposes
See

MAGI for child tax credit / credit for other dependents
Child Tax Credit (CTC), Credit for Other dependents (ODC). See

MAGI for education credit purposes
See

MAGI for the FAFSA® form
FAFSA® (Free Application for Federal Student Aid) form. See

MAGI for traditional IRA purposes
See

MAGI for Roth IRA purposes
See

MAGI for net investment income tax
See Form 8960

MAGI for premium tax credit
See

MAGI for rental passive loss allowance
See

MAGI for student loan interest deductibility
See

MAGI for Medicare premiums (IRMAA tiers)
This MAGI is defined in 42 U.S.C. 1395r(i)(4), from the Social Security Act §1839: (4) Modified adjusted gross income. (A) In general.—For purposes of this subsection, the term “modified adjusted gross income” means adjusted gross income (as defined in section 62 of the Internal Revenue Code of 1986)— (i) determined without regard to sections 135, 911, 931, and 933 of such Code; and (ii) increased by the amount of interest received or accrued during the taxable year which is exempt from tax under such Code.

The words "determined without regard to" mean that any income not included in Form 1040 Adjusted Gross Income (AGI) due to those code sections must be added to AGI to calculate MAGI for the IRMAA tiers. 26 U.S. Code § 135 refers to income from U.S. savings bonds used to pay higher education tuition and fees. 26 U.S. Code § 911 refers to income from citizens or residents of the United States living abroad. 26 U.S. Code § 931 refers to income from sources within Guam, American Samoa, or the Northern Mariana Islands. 26 U.S. Code § 933 refers to income from sources within Puerto Rico.

Many web sites have incomplete information about this MAGI. For example, page 2 of mentions the tax-exempt interest but neglects to mention the necessary addition of the foreign items or income from US Savings bonds used to pay higher education tuition and fees.