What is MAGI for the car loan interest deduction?

Modified Adjusted Gross Income (MAGI) for this deduction is your Adjusted Gross Income (AGI) with certain deductions added back. For most taxpayers, MAGI is the same as or very close to AGI.

Does the phase-out apply per person or per return?

It applies per return. For married filing jointly, the $200,000 threshold and $10,000 deduction cap apply to the combined return, not to each spouse individually.

If my income varies year to year, does the phase-out change?

Yes. The phase-out is calculated each year based on that year's MAGI. If your income drops below the threshold in a given year, you get the full deduction for that year.

Can contributing to a 401(k) help me avoid the phase-out?

Yes. Traditional 401(k) contributions reduce your AGI (and therefore MAGI). Contributing the maximum $23,500 could move your MAGI below the phase-out threshold if you're close to the edge.

Car Loan Interest Deduction Phase-Out: Income Limits Explained

If you earn above certain income thresholds, your car loan interest deduction gets reduced — and eventually eliminated entirely. The phase-out starts at $100,000 in Modified Adjusted Gross Income (MAGI) for single filers and $200,000 for married filing jointly. Understanding exactly how the phase-out works can help you plan and potentially take steps to preserve more of your deduction.

This calculator provides estimates only and should not be considered tax advice. Consult a qualified tax professional for your specific situation.

Based on the One Big Beautiful Bill Act (OBBBA), signed July 4, 2025. This deduction is available for tax years 2025-2028.

Phase-Out Thresholds by Filing Status

Here are the exact income thresholds where the phase-out begins and where the deduction is completely eliminated:

Single filers: phase-out begins at $100,000 MAGI, deduction fully eliminated at $150,000
Head of Household: phase-out begins at $100,000, eliminated at $150,000
Married Filing Jointly: phase-out begins at $200,000, eliminated at $250,000
Married Filing Separately: phase-out begins at $100,000, eliminated at $150,000

How the Phase-Out Formula Works

The reduction is calculated as follows: for every $1,000 your MAGI exceeds the threshold, your maximum deduction is reduced by $200.

The formula: Phase-out reduction = floor((MAGI - threshold) / 1,000) × $200

Your deduction = max($0, $10,000 cap - phase-out reduction)

For single filers, the math works out to a complete phase-out over a $50,000 range ($100K to $150K). For joint filers, it's also a $50,000 range ($200K to $250K).

Phase-Out Examples

Example 1 — Single filer, MAGI $110,000: Exceeds threshold by $10,000. Reduction = 10 × $200 = $2,000. Maximum deduction = $10,000 - $2,000 = $8,000.

Example 2 — Single filer, MAGI $135,000: Exceeds threshold by $35,000. Reduction = 35 × $200 = $7,000. Maximum deduction = $10,000 - $7,000 = $3,000.

Example 3 — Married filing jointly, MAGI $220,000: Exceeds threshold by $20,000. Reduction = 20 × $200 = $4,000. Maximum deduction = $10,000 - $4,000 = $6,000.

Example 4 — Single filer, MAGI $150,000: Exceeds threshold by $50,000. Reduction = 50 × $200 = $10,000. Maximum deduction = $10,000 - $10,000 = $0. Fully phased out.

Strategies to Stay Below the Phase-Out

If your income is near the phase-out threshold, certain strategies may help preserve your deduction:

Maximize pre-tax retirement contributions — 401(k) contributions reduce your MAGI by up to $23,500 (2025 limit)
Contribute to a Health Savings Account (HSA) if eligible — another MAGI reduction of up to $4,300 for individuals
Time income and deductions — if you have flexibility in when you receive bonuses or other income, timing them to keep your MAGI below the threshold in a given year can preserve the deduction

These are legitimate tax planning strategies, but consult a tax professional for advice specific to your situation.

Frequently Asked Questions

Related Tools & Guides

Calculate Your Deduction After Phase-Out →Full Eligibility Guide →How Much Can You Save? →OBBBA Overview →