Section 179 and Bonus Depreciation on Your Next Excavator or Dozer: Timing the Tax Strategy

Every fall, contractors start hearing the same phrase from an accountant or a well-meaning equipment salesman: "get it before year-end for the tax write-off." For an excavator or dozer purchase, that advice isn't wrong, but it usually skips the details that determine whether the deduction actually helps you or just sounds good in a sales pitch. Section 179 and bonus depreciation are real, valuable tools for a construction business buying heavy equipment, but the numbers, the timing, and how you finance the purchase all matter more than the general advice suggests.

A note before any of this: the figures below reflect the general federal rules as they stand for the 2026 tax year. Section 179 limits, bonus depreciation percentages, and state conformity all change, and your specific situation, business structure, and state can shift the outcome. Confirm every number and every decision here with your tax professional before you act on it.

The 2026 Numbers, in Plain Terms

For tax years beginning in 2026, the Section 179 deduction allows a business to expense up to $2,560,000 of qualifying equipment placed in service during the year, subject to a taxable-income limitation. That deduction begins phasing out dollar-for-dollar once total qualifying purchases exceed $4,090,000, and it phases out completely at $6,650,000, figures that cover the overwhelming majority of construction businesses buying excavators and dozers, even multiple machines in a single year.

For most single-machine purchases, an excavator or dozer's total cost will fall well within Section 179's full deduction range without brushing up against the $4,090,000 phase-out threshold. It's larger contractors buying several machines in the same tax year, say, adding a dozer, an excavator, and a wheel loader across one strong year, who need to watch where their combined purchases land relative to the phase-out and full phase-out figures, since crossing those thresholds changes how much of the total is Section 179-eligible versus reliant on bonus depreciation instead.

Bonus depreciation works alongside Section 179 rather than instead of it. Under current law, bonus depreciation is generally 100% for qualified property, including heavy equipment, acquired and placed in service after January 19, 2025. Many businesses use both together: elect Section 179 first on priority purchases, then apply bonus depreciation to any remaining eligible basis. Unlike Section 179, bonus depreciation isn't limited by your taxable income the same way, which is part of why a growing construction business often layers both, and it's a large part of why the market for electric dozers and other next-generation equipment has an added tax angle worth understanding on top of the technology itself.

Financing Doesn't Cancel the Deduction — This Trips People Up

A surprising number of contractors assume the write-off only applies if they pay cash. It doesn't. Financing an excavator or dozer with a term loan generally doesn't prevent you from taking the full Section 179 deduction or bonus depreciation on the purchase; what matters is that the equipment is placed in service and used for business, not how you paid for it. That means you can pursue dozer financing on a Komatsu D65PX-18, keep your cash in the business for payroll and materials, and still take the deduction against the full purchase price in the year the machine goes to work. This is one of the more useful, and more overlooked, features of equipment financing for a growing contractor. Confirm the specific interaction with your financing structure with your tax professional before you count on it.

"Placed in Service" Is the Date That Matters, Not the PO Date

The deduction is tied to when the equipment is placed in service, meaning operational and ready for its intended use in your business, not when you signed the purchase order or made a deposit. Order a dozer in November and it's still sitting on a dealer's lot or in transit on December 31, and it does nothing for that tax year no matter how firm the commitment was. If you're timing an excavator financing decision around year-end tax planning, build in real lead time for delivery, and confirm with your dealer and your tax professional exactly when the machine will be considered placed in service.

New, Used, or Certified — Does It Matter for the Deduction?

Section 179 and bonus depreciation both apply to new and used equipment, as long as the used equipment is new to your business, meaning you didn't already own or lease it before this transaction. That opens the door to a wider range of purchases than many contractors assume, whether it's a new Hyundai HX260L excavator straight off a dealer floor or a used machine bought through a manufacturer-backed program like Cat Certified Used, which pairs an inspection standard and typically some warranty coverage with the used price point. The deduction doesn't discriminate between new and used the way some contractors expect it to. Confirm eligibility on your specific used-equipment purchase with your tax professional.

This matters in practice for a growing fleet: a contractor who buys a used, certified Komatsu or John Deere machine one year and a new Hyundai or Cat machine the next isn't choosing between getting the deduction and not getting it, they're choosing between machines, financing structures, and price points on a tax playing field that treats new and used purchases the same way at the federal level.

Lease Structure Changes the Tax Picture

How you finance the machine changes how the tax benefit shows up. A $1 buyout lease is generally treated like a purchase for tax purposes, which typically makes it eligible for the same Section 179 and bonus depreciation treatment as a loan. A fair market value (FMV) lease is usually treated as a true rental, meaning you deduct the lease payments as an operating expense as you make them, rather than depreciating the machine or taking a Section 179 deduction on it. Neither approach is better in every case; it depends on whether you want the large upfront deduction or the simpler, spread-out expense treatment, and this is exactly where you should walk through your specific lease-versus-loan decision with your tax professional before signing, since it directly affects which tax tool is even available to you.

Why State Taxes Can Tell a Different Story

Federal Section 179 and bonus depreciation rules are only half the picture. Many states don't fully conform to the federal bonus depreciation percentage, and some cap their own Section 179 limit well below the federal number. A demolition contractor or general contractor operating across state lines might take a large federal deduction while seeing a smaller benefit on a state return for the same excavator or dozer purchase. This is squarely a question for your tax professional, since state treatment varies and changes independently of federal law.

Why Timing Your Excavator or Dozer Purchase Against Your Tax Year Matters

A general contractor or excavation contractor with a strong income year has more use for a large Section 179 deduction than one coming off a slow year with limited taxable income to offset, since the deduction can't create a loss the way bonus depreciation sometimes can. That's a real strategic decision: sometimes it makes sense to accelerate a planned excavator or dozer purchase into the current tax year, and sometimes it makes more sense to wait a few weeks into the next one. Either way, that decision should be made with your tax professional looking at your actual numbers, not on a general rule about year-end deadlines.

The Rent Angle

Renting an excavator or dozer for the season doesn't create a depreciable asset at all, there's no Section 179 election available on a rental invoice, because you never owned anything to depreciate. A contractor who rents a dozer through a heavy grading season and a contractor who finances and owns the same class of machine may spend similar cash over that stretch, but only one of them walks away with a tax deduction and equity in a machine. That's on top of the total cost of ownership gap we've covered elsewhere, the tax treatment is simply one more way renting comes up short against financing for equipment you're using for more than a short stretch.

Land-clearing and grading contractors who rent through a single heavy season to avoid a commitment are the clearest example. If that same contractor instead financed a dozer for the season, even carrying a deposit, they'd close the year with a depreciable asset, meaningful tax planning options, and equity, none of which a rental invoice from a rental house can provide no matter how the numbers are structured.

Bottom Line

Section 179 and bonus depreciation are genuinely useful tools for a construction business buying an excavator or dozer, but the details, the 2026 dollar limits, the placed-in-service date, how your financing structure is classified, determine whether the deduction actually lands the way you expect. This is also a good moment to loop your tax professional in before you talk to a lender, not after: walking into a financing conversation already knowing how a purchase fits your tax year lets you structure the deal, timing, new versus used, loan versus lease, around the full picture instead of bolting tax planning on as an afterthought.

Ready to Talk Numbers?

This article covers strategy, not specific pricing, because your rate, term, and deposit depend on your credit profile, time in business, and the exact machine you're after. That's a conversation for a lender, not a blog post. When you're ready, visit our home page to see how BFC Equipment Loans works with construction businesses like yours, apply for financing to get real numbers on your next excavator or dozer, browse our equipment for sale and financing listings if you're still shopping, or subscribe to the blog for more financing strategy built for contractors, not accountants.