Section 179 for Dentists in 2026
Section 179 lets a dental practice deduct qualifying equipment in the year it's placed in service — financed or cash. Three rules govern the year-end decision: what qualifies, when "placed in service" actually happens, and the deduction cap. This post walks through each with CPA caveats.
What qualifies
Tangible personal property used >50% in the trade or business. For a dentist that includes CBCT, intraoral scanners, CEREC, chairs, sterilization equipment, lasers, computers, and off-the-shelf practice management software. Real estate doesn't qualify (different rules apply for qualified improvement property). Vehicles have separate caps.
New and used equipment both qualify — used CBCT bought from a refurbisher qualifies the same as a new unit, as long as it's new to your practice.
Placed in service — what it really means
Three boxes have to check: installed, calibrated, and capable of generating revenue. A CBCT sitting in a crate on 12/31 is not placed in service. A CBCT installed but not yet calibrated is not placed in service. A CBCT installed, calibrated, and used for a single phantom scan on 12/30 is placed in service.
The strictest CPA reading requires real patient use; common practice accepts an acceptance test or phantom scan. Get your CPA's interpretation in writing before relying on year-end timing.
Deduction limit and phase-out
The Section 179 deduction limit and the dollar-for-dollar phase-out threshold are indexed annually for inflation. As of the 2026 tax year filings, the deduction limit is $2,560,000 and the phase-out threshold is $4,090,000 in equipment placed in service. ALWAYS confirm current-year figures with a CPA — these numbers move every year and our publication may post-date their next update.
Bonus depreciation interaction
Section 179 stacks with bonus depreciation. If you exhaust your Section 179 (rare for general dental), the remaining basis can take bonus depreciation. Bonus depreciation percentages phase down annually under current TCJA rules; confirm the year's bonus percentage with your CPA.
The install timelines that govern year-end
CBCT: 4–6 weeks from order. Order by mid-November for current-year placement.
CEREC / chairside CAD/CAM: 2–3 weeks from order. Order by early December.
Intraoral scanners (iTero, Primescan): 1–2 weeks from order. Order by mid-December.
Dental chairs: 1–2 weeks plus operatory readiness. The bottleneck is the room, not the chair.