Definition
Your total income minus specific adjustments such as traditional IRA or HSA contributions and student loan interest. Many tax credits, deductions, and account eligibility rules phase out based on AGI or its close cousin, modified AGI.
Why it matters
AGI is the gatekeeper number of the tax code: Roth IRA eligibility, education credits, and many deductions phase out above AGI thresholds. Lowering AGI with pre-tax contributions can unlock benefits worth real money.
Example
A filer near a credit's income cutoff contributes more to a traditional 401(k) and an HSA. Those pre-tax dollars reduce AGI below the threshold, preserving a credit that would otherwise have phased out.
Related terms
This definition is educational, not financial, legal, or tax advice. U.S. rules and limits change; verify time-sensitive details with official sources. See our disclaimer.