IRS finalizes regulations for the auto loan interest deduction
A new deduction for qualified passenger vehicle loan interest became available in 2025. Now, the IRS has released final regulations for the deduction. They include several important tweaks to the proposed regs issued at the end of 2025. Here’s what you need to know, especially if you hope to claim the deduction on your 2026 federal income tax return.
Basics of the deduction
The new deduction was created by the One Big Beautiful Bill Act (OBBBA). You don’t have to itemize deductions to claim it — it’s available both to nonitemizers who claim the standard deduction and to itemizers.
The OBBBA defines qualified passenger vehicle loan interest as interest paid or accrued during the tax year on debt incurred by a taxpayer after December 31, 2024, for the purchase of a qualifying vehicle for personal use. The debt must be secured by a “first lien,” meaning the lender generally has priority over other creditors’ claims to the vehicle until the loan is paid off.
Under the OBBBA, a qualifying vehicle must be a car, minivan, van, sport utility vehicle, pickup truck or motorcycle with a gross vehicle weight rating of less than 14,000 pounds. The original use of the vehicle must begin with the taxpayer; leased or used vehicles don’t qualify.
The deduction is also limited to vehicles assembled in the United States, as determined by the final assembly location. Remember that not every vehicle sold by an American manufacturer necessarily has its final assembly in this country. Conversely, some “foreign” vehicles may have their final assembly in the United States.
Dollar and income-based limits
The deduction is generally limited to $10,000 per year. If the deduction is a primary motivator in purchasing a new vehicle, bear in mind that most taxpayers won’t qualify for the full $10,000.
For example, assume you purchase a new vehicle before year end and finance $50,000 of the price at a 6.5% interest rate for five years. The total interest over that time will be approximately $8,700. But your deduction for each eligible tax year would be limited to qualifying interest paid that year. Also, the deduction is available only through 2028, unless lawmakers extend it. So your annual deduction would be only a fraction of the total $8,700 of interest. And you’d be able to deduct the total amount only if the tax break is extended beyond 2028.
Your annual deduction could be further reduced based on your income. The deduction begins to phase out when modified adjusted gross income (MAGI) exceeds $100,000, or $200,000 for married couples filing jointly. The otherwise allowable deduction is reduced by $200 for every $1,000 — or fraction of $1,000 — of MAGI above those thresholds.
Once MAGI reaches $150,000 or $250,000, respectively, the deduction isn’t available. Depending on how much qualifying interest you pay, your deduction could be fully phased out at a MAGI that’s substantially less than $150,000 (or $250,000 if you’re a joint filer).
Finally, keep in mind that deductions reduce your taxable income, not your taxes dollar-for-dollar. So your tax savings will be only a portion of the amount deducted.
The final regs
Like the proposed regs, the final regs address a range of issues related to the deduction. The following may be the most notable if you might be eligible for it:
Qualifying debt. The proposed regs specified that debt qualified only to the extent incurred for a qualifying vehicle purchase. It also qualified for other items or amounts directly related to the purchase and “customarily financed” in the same transaction, including vehicle service plans, extended warranties, sales taxes and vehicle-related fees.
In response to comments received on the proposed regs, the final regs identify additional examples of costs that can be included in a qualifying vehicle loan:
- Guaranteed asset protection coverage,
- Credit insurance products,
- Repair plans,
- Vehicle protection products,
- Key fob replacement plans, and
- Certain vehicle accessories.
The final regs make clear that whether items or amounts are customarily financed in a qualifying vehicle purchase transaction and are directly related to the purchase of the vehicle is determined on an industry-wide basis and not by reference to the financing terms of a particular lender. Interest on credit card debt related to a vehicle purchase, however, generally doesn’t qualify because the debt usually isn’t secured by the vehicle.
Negative equity. So-called negative equity occurs when you trade in a vehicle that still has debt exceeding that vehicle’s value and you roll that excess debt into the financing for a qualifying new vehicle. The proposed regs would have excluded this amount from qualifying debt. Industry commenters cited the administrative burden of tracking the separate loan components when requesting that the entire loan count for purposes of the deduction.
The IRS was unmoved, though. Interest attributable to the negative-equity portion of the loan doesn’t qualify for this deduction under the OBBBA. The final regs retain the requirement to allocate interest and principal payments proportionately between qualifying and nonqualifying debt. But any down payment is applied first against negative equity and any other amounts that aren’t incurred for the purchase of the vehicle or directly related to the purchase and customarily financed in such a transaction.
Original use and personal use. The final regs recognize that some states require dealers to title or register demonstrator vehicles. Under the proposed regs, this could have resulted in the original use commencing with the dealer and not a subsequent purchaser. The final regs therefore provide that the original use of a vehicle held by a dealer won’t commence with the dealer if the vehicle is held primarily for sale to customers. But original use of a vehicle begins with a purchaser only if the loan documentation treats the vehicle as a new vehicle.
The final regs retain the proposed regs’ provision establishing that the personal use requirement applies only when you incur the debt. At that time, you must expect that you, your spouse or certain relatives will use the vehicle for personal purposes more than 50% of the time over your anticipated ownership period. But if it turns out the actual use varies from the expected use at the time you incur the debt, it won’t change the personal use determination.
Cover your bases
Taxpayers hoping to take advantage of this temporary deduction, especially for 2026, should tread carefully. A single misstep in vehicle choice, documentation requirements or another area could cost you. For example, you must include the vehicle identification number (VIN) on your return for each year you claim the deduction. Contact us to discuss whether you qualify for the deduction and, if so, how to maximize its benefits.
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