Blog · 2026-09-28
How to use AssemblyAlert’s car-loan calculators for the OBBBA interest deduction
Free VIN check · US assembly
Free VIN check — was it assembled in the US?
Paste the 17-character VIN. This reads NHTSA PlantCountry. It is a data check, not tax advice, and it does not decide whether any loan is deductible.
The tools at /calculators are client-side illustrations. They estimate payments, interest under the $10,000 cap, lease-vs-buy cash, affordability, and extra principal. They never decide whether a loan is deductible.
This page is a walkthrough, not new phaseout math. For bracket illustrations see How much is the deduction worth?. For MAGI rows see MAGI phaseout examples. This page does not decide a return. AssemblyAlert never says a loan is deductible and never says a reader qualifies.
The IRS Working Families Tax Cuts pages describe a temporary deduction for tax years 2025 through 2028 for interest on a loan used to purchase a qualified vehicle, up to $10,000 of qualified interest a year, with a MAGI phaseout over $100,000 ($200,000 joint). Topic no. 505 repeats the tax-year window and the United States final-assembly rule.
Check plant country now on the free homepage VIN checker. Calculators estimate interest dollars. Assembly still needs the VIN. Paste the 17-character VIN. AssemblyAlert reads NHTSA vPIC `PlantCountry`. It passes US assembly only if `PlantCountry` is exactly `UNITED STATES (USA)`. Puerto Rico is not a pass. VIN position 1 is a WMI screen, never the verdict. Plant-country Pass is not the deduction.
You can also paste that VIN in the free checker on this page.
What the page does — and does not
Open /calculators. Five sections sit on one page:
| Jump link | What it models | What it does not check |
|---|---|---|
| #payment | Monthly payment and an amortization table | Assembly, original use, loan date |
| #interest | Calendar-year interest under the $10,000 cap, optional MAGI slider | Whether the interest is qualified |
| #lease | Buy vs lease cash; lease illustrated deduction is $0 | A purchase loan’s other IRS gates |
| #afford | Max principal at a payment-budget percent | MAGI, VIN, or leases |
| #payoff | Extra monthly principal and interest saved | The deduction |
The calculators do not check assembly, original use, personal use, or loan date. Used vehicles do not qualify. Lease payments do not qualify. A loan still has to originate after December 31, 2024. The VIN must be on the return for any year the deduction is claimed — where it goes.
1. Estimate interest under the $10,000 cap
Start with Payment calculator: principal, APR, term. That schedule feeds the rest of the page.
Then open Interest / OBBBA cap estimator. Set loan start year and month and the tax year you want to illustrate. The tool estimates interest paid in that calendar year from the amortization, then applies the IRS $10,000 annual cap.
If first-year interest is $8,400, the illustrated amount under the cap is $8,400. If first-year interest is $12,400, the illustrated amount under the cap is $10,000 before any MAGI reduction. That is the same $10,000 line as How much is the deduction worth? — a cap on qualified interest, not a cash rebate and not sticker price.
Leave MAGI empty if you only want the cap. The page says “Off — cap only, no MAGI reduction.”
2. Treat MAGI as a separate illustration
The MAGI slider is optional. It does not compute your MAGI and does not file a return.
If you turn it on, the tool applies the same OBBBA-statute illustration as the MAGI phaseout examples: $200 per $1,000 (or fraction) over $100,000 (single / most) or $200,000 (joint). That slope reaches $0 at $150,000 / $250,000. Filing status on the page only changes which threshold the slider uses.
A number under the cap after MAGI is still an illustration. Plant-country, lease, used-vehicle, and loan-date gates stay separate.
3. Lease vs buy prints $0 for a lease
Lease vs buy is a cash comparison: buy down payment plus payments versus lease drive-off plus lease payments. Residual is informational.
The IRS Working Families Tax Cuts pages state that lease payments do not qualify. The tool prints Lease illustrated interest deduction: $0. That flag is the point. It does not convert a lease into a purchase loan. See Do auto leases qualify?.
A purchase side still has to clear every other gate, including used vehicles do not qualify. See Do used cars qualify?.
4. Then check PlantCountry
Affordability and extra principal are lot-talk math — a payment budget and interest saved if you add principal. They do not score the deduction.
After the dollars, use the free homepage VIN checker or the checker on this page. See Was my car assembled in the US?. This site passes only `PlantCountry === UNITED STATES (USA)`. Puerto Rico fails. VIN position 1 is not the verdict.
Keep Form 1098-VLI with the loan packet when it arrives. Use the 2025–2028 checklist as the gate list. Fact cards print the same IRS-stated lines, including the interest cap.
Other IRS gates a calculator does not rewrite
- Tax years 2025 through 2028
- Up to $10,000 of qualified interest
- MAGI phaseout over $100,000 ($200,000 joint)
- Loan originated after December 31, 2024
- Used to purchase a vehicle — lease payments do not qualify
- Original use starts with the taxpayer — used vehicles do not qualify
- Personal use; lien; GVWR under 14,000 pounds
- US final assembly — `PlantCountry === UNITED STATES (USA)`
- VIN on the return for any year the deduction is claimed
FAQ
Do these tools say I qualify?
No. They are client-side illustrations. This site never says a loan is deductible and never says a reader qualifies.
Does the cap estimator check assembly?
No. Paste the VIN in the free homepage VIN checker.
Why is the lease deduction $0?
Lease payments do not qualify.
Cite the IRS Working Families Tax Cuts pages. Confirm the vehicle, the loan, and the return with a preparer. Not tax advice. Not affiliated with the IRS or NHTSA. Owned by Record of Sale, LLC.
Calculators · Facts · Homepage VIN checker · Commercials (18+)