Section 179 and Bonus Depreciation on GMC and Buick Vehicles: A 2026 Year End Checklist for Gurnee Business Owners
Last reviewed: October 2026
Every fall we get the same call from contractors, landscapers, snow removal crews, real estate agents and small business owners around Gurnee: “If I buy a truck before the end of the year, can I write it off?” Often the answer is some version of yes, through Section 179 and bonus depreciation. But the details matter, and getting one of them wrong can cost you the deduction. So here’s the checklist we walk people through. We sell trucks, we don’t do taxes, so take all of this to your tax professional before you decide.
Personal buyer looking for the auto loan interest deduction? That’s a separate program. See our GMC loan interest deduction page.
- 1Confirm business use
- 2Check the GVWR
- 3Match the model to the bucket
- 4Get it in service by 12/31
- 5Keep your records
1. Confirm It’s Really a Business Vehicle
Section 179 and bonus depreciation are business deductions. The vehicle has to be used more than 50% for business in the year you put it in service. Exactly 50% doesn’t qualify, and if you use it partly for personal driving the deduction drops by that share. A truck that’s 80% work and 20% weekends gets 80% of the numbers below. This applies whether you’re a sole proprietor, an LLC, an S corp or a larger company with a fleet.
2. Check the GVWR on the Door Jamb
The single number that decides which rules apply is the gross vehicle weight rating, or GVWR. It’s on the certification label inside the driver’s door jamb. Over 6,000 lbs puts the vehicle in the heavy category where the big first year deductions live. At or under 6,000 lbs puts it under the regular passenger vehicle limits, which GM lists at up to $20,300 in the first year. GVWR changes with cab, bed, drivetrain and trim, so two Sierras sitting next to each other on our lot can land on opposite sides of that line. Ask us to pull the label on the exact unit before you sign anything.
3. Match the Model to the Right Bucket
GM publishes its own lists for GMC and Buick. For 2026 they break down like this. Confirm the GVWR on the specific vehicle.
| Bucket | Models GM lists | What GM says |
|---|---|---|
| Trucks and vans over 6,000 lbs GVWR | Sierra 1500 (standard and long bed), Sierra 2500 HD, Sierra 3500 HD, Sierra 3500 HD Chassis Cab, Savana Cargo, Savana Cutaway, Savana Passenger (10+ seats) | Up to 100% of purchase price (Section 179) |
| SUVs and short bed trucks over 6,000 lbs GVWR | Sierra 1500 short bed incl. Denali, Sierra EV, Yukon, Yukon XL, Acadia, Canyon, Buick Enclave incl. Avenir | Up to 100% of purchase price (Section 179 up to the $32,000 SUV cap plus bonus depreciation) |
| 6,000 lbs GVWR or less | Terrain, Buick Envista, Encore GX, Envision | Up to $20,300 first year |
Here’s why the middle row has that extra note. For tax years beginning in 2026, Section 179 on a sport utility vehicle over 6,000 lbs GVWR is capped at $32,000. Bonus depreciation picks up the rest. Under the 2025 tax law, 100% bonus depreciation applies to qualifying property acquired and placed in service after January 19, 2025, so GM can say “up to 100%” on a Yukon XL or Enclave even with the cap. Heavy trucks and cargo vans in the top row aren’t subject to the SUV cap, which is why they’re the simplest case. The overall Section 179 limit for 2026 is $2,560,000 with a phase out starting at $4,090,000, which most Lake County businesses won’t come close to.
See what’s on the lot: GMC Sierra 1500 in Gurnee, Sierra 1500 inventory, GMC commercial vehicles, and all new GMC and Buick inventory.
Which bucket a vehicle falls in depends on its GVWR. We’ll pull the label for you.
4. Get It in Service by December 31
For a 2026 deduction the vehicle has to be placed in service by December 31, 2026. In plain terms that means delivered, titled and ready to work, not sitting on order. HD trucks, chassis cabs and upfitted vans can take weeks to locate or build, so if a year end purchase is part of your plan, start now instead of the last week of December. If the right unit isn’t on our lot we can search dealer stock and incoming allocations.
Two quick examples of how the pieces fit. A snow removal company buys a Sierra 3500 HD for $75,000, uses it 100% for work, and takes delivery in November. Because it’s a heavy truck, the whole $75,000 may be deductible in 2026 under Section 179, subject to business income and overall limits. The same company buys a Yukon XL for $75,000 for the owner. Section 179 is capped at $32,000, the remaining $43,000 may qualify for 100% bonus depreciation, and if the owner drives it 75% for business, every number gets multiplied by 75%. These are illustrations, not quotes. Your real deduction depends on business income, entity type, Illinois rules and other things your tax pro will know.
5. Keep the Paperwork
Keep the purchase agreement, the financing paperwork if any, a copy of the door jamb label or window sticker showing GVWR, and a mileage log that separates business from personal miles. A log app on your phone is fine. Your tax professional will need all of it to support the deduction, and it protects you if anyone ever asks. Financing through our finance center doesn’t change eligibility, so you don’t have to pay cash to qualify.
FAQs
Can I use Section 179 on a leased GMC?
Section 179 and bonus depreciation apply to purchases, including financed purchases. Leases work differently. Ask your tax advisor what applies to your lease.
Does a pre-owned truck or SUV qualify?
It can, as long as it’s new to your business and meets the same use and weight rules. Take a look at our pre-owned inventory.
Is the Sierra 1500 over 6,000 lbs GVWR?
Many configurations are, which is why GM lists it in both of the heavy categories, but it depends on cab, bed and drivetrain. We’ll check the label on the unit you’re looking at.
What’s the difference between Section 179 and bonus depreciation?
Section 179 is an election to expense the cost of equipment in the year you place it in service, with dollar limits and the SUV cap. Bonus depreciation is a separate first year allowance, currently 100% for qualifying property, that can apply on top of Section 179. Your tax pro will decide how to use each one.
What if I miss December 31?
Then it’s a 2027 deduction instead, under whatever the 2027 limits turn out to be. The deduction doesn’t go away, it just moves to the year the vehicle goes into service.
Let’s Find the Right Truck, Van or SUV
We’re at 5589 Northridge Drive in Gurnee, just off the Tri State near Gurnee Mills, and we’ve been a family owned GMC dealer in Chicagoland since 1998. We work with business buyers from Gurnee, Waukegan, Libertyville, Grayslake, Zion and up across the Wisconsin line in Kenosha. Call our sales team at (847) 693-4799 or use the form below, tell us what the vehicle needs to do, and we’ll find the right fit and get you the GVWR. Then take it to your tax professional and let them confirm what it means for your return.
Find a Section 179 Eligible Vehicle Before Year End
Tell us what you need the vehicle to do and when you need it in service. We’ll check our lot and incoming units and get back to you.
Each purchaser’s tax situation is unique. Available tax benefits and the applicable federal and state tax laws, regulations and guidelines are subject to change without notice. Customers must consult their own tax advisor to determine the proper tax treatment of any vehicle purchase. For more information visit www.irs.gov. This page is for informational purposes only and should not be construed as tax advice or as a promise of the availability or amount of any tax benefit or reduced tax liability. Vehicle eligibility is based on manufacturer published lists as of October 2026 and on the GVWR of the specific vehicle. Woody Buick GMC of Gurnee is not a tax advisor.