Two people can buy the same model SUV and get different federal tax results. One vehicle may have undergone final assembly in the United States and satisfy the new car-loan-interest rules. Another vehicle carrying the same model name may have been assembled abroad and fail the test.

Treasury and the IRS have now finalized the regulations for qualified passenger vehicle loan interest. The final rules were published in the Federal Register on Sept. 8, 2026, and Treasury Decision 10054 appears in Internal Revenue Bulletin 2026-39. The regulations state an effective date of Nov. 9, 2026, while their applicability provision covers taxable years beginning after Dec. 31, 2024, and before Jan. 1, 2029.

The underlying deduction was created by Public Law 119-21 for tax years 2025 through 2028. It can be available whether or not a taxpayer itemizes deductions. The headline limit is $10,000 of qualified interest per federal return, but that number comes after a series of eligibility tests and before an income-based phaseout.

The vehicle has to pass more than a make-and-model test

The loan must have been incurred after Dec. 31, 2024, to purchase a qualifying passenger vehicle for personal use, and it generally must be secured by a first lien on that vehicle. The vehicle must be a car, minivan, van, SUV, pickup truck or motorcycle with a gross vehicle weight rating below 14,000 pounds.

The original use of the vehicle also has to begin with the taxpayer. That keeps ordinary used-car purchases outside the deduction. A lease does not qualify, and buying the vehicle at the end of a lease generally does not fix the original-use problem because the original use usually began with the leasing company.

Dealer demonstrators get a more specific rule. If a dealer held the vehicle primarily for sale to customers, using it for test drives does not necessarily cause original use to begin with the dealer. A later purchaser may still satisfy the original-use requirement. A dealer service or loaner vehicle, by contrast, can have a different result if the dealer used it for business operations rather than primarily holding it for sale.

Final assembly must occur in the United States. The final regulations reject a brand-level shortcut because vehicles with the same make and model can come from different assembly plants. A taxpayer may rely on the plant of manufacture reported through the VIN or the final assembly point on the vehicle label. The National Highway Traffic Safety Administration’s VIN Decoder is one way to check the plant information. The VIN must also be reported on the federal return; without it, the interest cannot be treated as qualified passenger vehicle loan interest.

Mixed use does not automatically disqualify the loan

The final regulations test personal use when the debt is incurred. During the period the taxpayer expects to own the vehicle, it must be expected to be used more than 50% of the time for personal purposes by the taxpayer, a spouse or certain related individuals.

For example, a taxpayer who buys a pickup expecting 70% personal use and 30% use in a side contracting business can satisfy the personal-use test if the other requirements are met. A taxpayer who expects 60% business use and 40% personal use cannot.

The test is not repeated each year, and later actual mileage does not change that initial personal-use determination. Business use can still affect how interest is claimed: interest that is otherwise deductible as a business expense may be claimed under the vehicle-loan rules, as business interest or split between the two, subject to the applicable limits, but the same interest cannot be deducted twice.

The $10,000 cap is per return, then income can cut it down

The final regulations confirm that the $10,000 annual limit applies per federal tax return regardless of filing status. A married couple filing jointly does not receive a $20,000 cap merely because each spouse financed a separate qualifying vehicle. Interest from multiple qualifying loans can be aggregated, but the return still has one $10,000 ceiling.

Modified adjusted gross income then reduces the otherwise allowable deduction. The phaseout starts above $100,000 for every taxpayer other than a married couple filing jointly — including single, head-of-household and married-filing-separately filers. Joint returns use a $200,000 threshold. The reduction is $200 for each $1,000 — or portion of $1,000 — above the applicable threshold.

Consider a single filer with $6,400 of otherwise qualified vehicle-loan interest and modified adjusted gross income of $112,400. The $12,400 excess over the threshold rounds up to 13 blocks of $1,000. At $200 a block, the phaseout cuts $2,600 from the claim and leaves a $3,800 deduction.

The starting interest amount changes where the deduction reaches zero. For a single filer, a $4,000 claim is fully phased out by $120,000 of modified adjusted gross income; a claim at the $10,000 cap lasts until $150,000.

Refinancing can preserve the deduction, but cash-out debt does not automatically come along

The final rules also clarify what counts as debt incurred for the purchase. Amounts customarily financed with the vehicle — such as an extended warranty, sales tax, title and registration fees and a dealer document fee — can be included when they are directly related to the vehicle purchase. Debt used to pay negative equity on a trade-in or to finance an unrelated item does not qualify. If one contract finances both qualifying and nonqualifying amounts, the regulations require interest to be allocated between them in proportion to the qualifying and nonqualifying debt.

A later refinance can preserve qualified status for the portion tied to the original qualifying balance. The regulations give an example in which a taxpayer refinances a $30,000 remaining qualifying loan with a new $38,000 loan. Only $30,000 of the refinanced balance remains within the qualified vehicle-loan rules; interest attributable to the extra $8,000 does not.

For a calendar year in which a lender receives at least $600 of interest on a specified passenger vehicle loan, the lender must furnish the borrower a statement by Jan. 31 of the following year. The regulations identify Form 1098-VLI, Vehicle Loan Interest Statement, for this reporting. The form includes the interest amount and vehicle and loan details, but it is a starting point, not a guaranteed deduction: the taxpayer remains responsible for applying the $10,000 cap, the income phaseout and the other eligibility rules. A lender may choose to report less than $600 but is not required to do so.

Keep the original purchase and loan documents, the VIN, evidence of the assembly location, the lender statement and the deduction calculation. Before estimating the tax benefit, match the specific vehicle and loan to the rules, then run the income phaseout.

Sources

Primary sources, last checked Sep. 24, 2026:
IRS Internal Revenue Bulletin 2026-39 — T.D. 10054, Car Loan Interest Deduction
26 U.S.C. §163(h)(4) — Qualified passenger vehicle loan interest
IRS Topic No. 505 — Interest expense
NHTSA VIN Decoder