Tax

MAGI Phase-out

Last updated: July 2026 Reviewed & verified by Galvin Mendonca

Definition

The income range over which a tax deduction, credit, or account eligibility is gradually reduced to zero.

Key Takeaways

  • Gradually reduces tax deductions, credits, or account eligibility as MAGI rises.
  • Ensures tax benefits target low- and middle-income taxpayers.
  • Features a starting threshold (where reduction begins) and an ending limit (where benefit is zero).
  • Each tax provision has distinct phase-out thresholds depending on filing status.

Detailed Explanation

A MAGI Phase-out represents the gradual reduction and eventual elimination of a tax benefit as a taxpayer's Modified Adjusted Gross Income (MAGI) increases. The IRS uses phase-outs to ensure that tax credits, deductions (such as those under the OBBBA), and retirement account contributions (like Roth IRAs) benefit low- and middle-income earners rather than high-income taxpayers.

During a phase-out, the maximum allowable tax benefit is reduced proportionally. For example, under OBBBA, the $10,000 auto loan interest deduction phases out between $100,000 and $150,000 MAGI for single filers, meaning every dollar of MAGI above $100,000 reduces the deductible cap until it reaches zero at $150,000.

Real-World Example Sarah, a single filer with $120,000 MAGI, wants to claim the OBBBA auto loan interest deduction (max $10,000). The phase-out starts at $100,000 and ends at $150,000 MAGI. She is $20,000 into the $50,000 phase-out range, meaning her deduction is reduced by 40% ($20,000 ÷ $50,000). Instead of the full $10,000 deduction, she can only deduct $6,000 ($10,000 × 60% remaining eligibility). If her MAGI were $160,000, she would be completely phased out and receive zero deduction.

Disclaimer: Definitions and explanations on this glossary page are provided strictly for general educational and informational purposes. They do not constitute formal financial, investment, legal, or tax advice. Financial regulations, caps, and limits change frequently. Always consult a qualified professional before making any financial decisions.
Advertisement