How Can Construction Companies Maximize Vehicle Tax Deductions in 2026?

In Brief:

Section 179 lets construction companies deduct the full purchase price of qualifying vehicles in the year they’re placed in service, up to $2.56 million for 2026, with no phase-out until purchases exceed $4.09 million.
Heavy vehicles over 14,000 pounds GVWR, such as dump trucks and cargo vans, can often be fully expensed under Section 179 alone, while passenger vehicles between 6,001 and 14,000 pounds are capped at $32,000.
Bonus depreciation is back at 100% for property placed in service after January 19, 2025, thanks to the One Big Beautiful Bill Act, and can cover costs above the Section 179 cap on eligible vehicles.
A vehicle must be used more than 50% for business to qualify for these deductions, and detailed, contemporaneous mileage logs are required to substantiate that use if the IRS ever asks.
If business use drops below 50% after a deduction is taken, or the vehicle is sold or traded in, the IRS can require recapture of some or all of the deduction as ordinary income.
Financing a vehicle doesn’t disqualify it from Section 179; businesses can still deduct the full price in the year it’s placed in service while spreading out loan payments over time.

Construction companies are known for running large vehicle fleets. Pickups, flatbeds, cargo vans, and other specialized equipment are part of every work site. Those leases and purchases, and the ongoing costs of keeping a fleet running, can generate valuable tax deductions. When decision-makers understand the available benefits, they can help significantly reduce tax liability and improve cash flow, potentially by thousands of dollars in a single year. Through a combination of the IRC 179 (Section 179) deduction, bonus depreciation, and other potential deductions, these savings become possible. To help clients, prospects, and others, JLK Rosenberger has summarized the key details below.

Tax Planning Opportunities

- Section 179 — This allows a business to deduct the full purchase price of a qualifying vehicle in the year it is placed in service. For 2026, the deduction limit is $2.56 million. The phase-out does not begin until total qualifying purchases exceed $4.09 million, so most construction companies have significant room to work with.The Section 179 vehicle limits are based on gross vehicle weight rating (GVWR), which is the manufacturer’s maximum loaded weight rather than curb weight. Vehicles primarily designed to carry passengers with a GVWR between 6,001 and 14,000 pounds are limited to $32,000 under Section 179. Vehicles over 14,000 pounds, like dump trucks, cement trucks, and cargo vans, are treated like other heavy equipment and not subject to this cap; these heavy-duty vehicles can often be fully expensed under Section 179 alone.
  To qualify, the vehicle must be used more than 50% for business, and it must be placed in service before December 31 of the tax year. It generally applies to both new and used vehicles, as long as the vehicle is new to the owner.
  
  A vehicle does not have to be paid for in full to qualify for Section 179. Businesses are still able to finance a qualifying vehicle and then deduct the purchase price in the year it is placed in service. This may allow companies to spread payments over several years while receiving the tax benefit upfront.

- Bonus Depreciation — This provision allows an additional first-year deduction on top of Section 179. The One Big Beautiful Bill Act (OBBBA), signed July 4, 2025, restored the rate to 100% for property placed in service after January 19, 2025, reversing a multi-year phase-down that had dropped the rate to 60% in 2024 and 40% for the first few weeks of 2025.For vehicles subject to the $32,000 Section 179 cap, bonus depreciation may cover the rest. For example, a $90,000 SUV generates a $32,000 Section 179 deduction and a $58,000 bonus depreciation deduction, allowing the business to recover the full cost in the first year. Work trucks and heavy equipment can often be fully expensed under Section 179 alone, making bonus depreciation unnecessary in many situations.
  It’s important to note that Section 179 is limited by business taxable income and cannot create a loss. Bonus depreciation carries no such restriction and can generate or increase a net operating loss, which then carries forward to offset future income.
  
  Section 179 and bonus depreciation also differ in how the elections are made. Section 179 generally allows businesses to choose which qualifying assets receive the deduction, while bonus depreciation follows election rules that apply by asset class. Because those differences can affect the tax outcome, businesses should consult with tax advisors to determine the most beneficial approach for the specific situation.

Operating Expenses — The actual expense method allows a business to deduct the day-to-day costs of operating a fleet as ordinary and necessary business expenses. Fuel, oil, tires, repairs, maintenance, insurance, registration fees, and loan interest on business-owned vehicles all qualify. Lease payments are also generally deductible.The alternative is the standard mileage rate, which substitutes a flat per-mile deduction for actual costs. For 2026, the standard mileage rate is 72.5 cents per business mile. However, a business that takes Section 179 or bonus depreciation on a vehicle cannot use the standard mileage rate for that vehicle.
Construction fleets will need to track costs carefully and ensure each vehicle clears the 50% business use threshold to maximize what the business recovers at tax time.

Business Use Requirements

Business use also affects the available deduction. A truck used 80% for business generates deductions equal to 80% of the otherwise allowable amount. Commuting between home and a job site does not count as business use.

The IRS also requires businesses to substantiate how a vehicle is used. In most cases, this means maintaining contemporaneous records that support the business use claimed on the tax return. This includes keeping detailed mileage logs throughout the year, not just reconstructed at year-end. Each entry should have the date, destination, business purpose, and miles driven. Those records substantiate the deduction if the return is audited and protect against recapture if business use is questioned later.

Some permanently modified work vehicles may be exempt from the mileage log requirements that apply to most business vehicles because they are not likely to be used for personal purposes. This may include pickups and vans with permanent company branding together with hydraulic lift gates, permanent tanks, fixed shelving, dedicated cargo space, or other specialized equipment.

If mileage records are incomplete, the Cohan Rule may provide limited relief in certain circumstances, if there is other credible evidence to substantiate business use. However, it should not be relied upon in place of maintaining mileage logs.

After claiming the deduction, businesses must also continue to meet the applicable business use requirements. If business use on a vehicle drops below 50% in any year after the deduction was taken, the IRS requires recapture of a portion of the deduction as ordinary income. Additionally, selling or trading in a business or mixed-use vehicle may also trigger depreciation recapture. Any gain up to the amount of depreciation previously claimed, including Section 179 and bonus depreciation, may be taxed as ordinary income.

Vehicles titled in the business name receive different treatment from personally owned vehicles. Personal vehicles used for business require either reimbursement through a formal accounting method or a deduction on the owner’s return.