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MAGI and the Car Loan Interest Deduction
A recordkeeping guide to finding the MAGI input used in the current car-loan-interest deduction calculation.
Matthew NewmanAuthor and editorial reviewer · Primary sources checked 2026-09-01MAGI and the Car Loan Interest Deduction is easiest to manage when the decision is broken into a few visible checks instead of one confident guess. Identify the filing-year form, income sources, filing status, and IRS definition used for the phaseout.
This guide is educational recordkeeping information, not tax advice. Check the current IRS instructions or ask a qualified tax professional before filing.
Start with the source
Identify the filing-year form, income sources, filing status, and IRS definition used for the phaseout.
Write down the exact detail that controls the result: MAGI and the Car Loan Interest Deduction. If the source is incomplete, mark the item for review rather than filling the gap from memory.
Work through the decision
Keep source documents and the year-specific MAGI figure with the vehicle interest record.
For example, The number on a pay stub or bank statement is not automatically the MAGI used by the worksheet. Use the example to understand the workflow, not to promise the same outcome in a different situation.
Use the result carefully
Have a tax professional confirm the calculation when the return has multiple income items.
The common mistake is to use a single income field as a filing-ready MAGI result. Keep the original record, assumptions, and review date together so the result can be corrected when the source changes.
Authoritative sources
Sources were last reviewed on . We prefer primary government and platform documentation, link claims to their source, and recheck articles when rules or app behavior changes. Always verify the source for the relevant year or situation.