Dental Practice Tax Deductions: Equipment, Supplies, and Every Expense You Can Write Off

Almost everything a dental practice spends is deductible; the questions are when and where on the return. Equipment, from the operatory chair to a $175,000 CBCT unit, comes off in the year it’s placed in service through Section 179 (up to $2,500,000 for 2025 and 2026) or 100% bonus depreciation, which is permanent again for property acquired after January 19, 2025. Supplies, lab fees, CE, malpractice premiums, software, marketing and staff costs are current expenses under IRC 162. The money gets missed on the smaller lines: merchant fees, patient-financing discounts, amalgam waste, the home office, and the start-up costs that should have been amortized from the month the doors opened.

How is dental equipment depreciated?

In full, in year one, for nearly every practice. Section 179 lets you expense up to $2,500,000 of equipment placed in service in 2025 or 2026 (indexed for inflation starting 2027), phased out above $4,000,000 of purchases and capped at business taxable income. Bonus depreciation under IRC 168(k) is 100% with no cap and no income limit for property acquired after January 19, 2025. Either way, a $175,000 CBCT bought in 2026 is a $175,000 deduction in 2026.

Asset	MACRS class	If not expensed	Section 179	Bonus
Chairs, delivery units, autoclaves, compressors, CBCT, CAD/CAM mill, handpieces	Asset class 57.0, personal and professional services: 5-year	20% in year one, half-year convention	Yes	Yes
Computers, servers, digital sensors, intraoral scanners	Asset class 00.12, information systems: 5-year	20% in year one	Yes	Yes
Desks, cabinetry that isn’t a structural component, reception furniture	Asset class 00.11, office furniture: 7-year	14.29% in year one	Yes	Yes
Operatory build-out inside a leased or owned building (interior, non-structural)	Qualified improvement property: 15-year	5% in year one	Yes, by election as qualified real property	Yes
The building itself, structural components	Nonresidential real property: 39-year	up to 2.46% in year one (mid-month convention)	No	No

• The class assignment matters when you don’t expense, and when your state doesn’t follow federal expensing. The IRS table of class lives in Publication 946 gives asset class 57.0 “a 9-year class life and a 5-year recovery period for GDS,” class 00.12 (computers) a 5-year period, and class 00.11 (furniture) a 7-year period. Dental chairs and imaging units are assets used in a professional service business and sit in 57.0, so the common habit of calling them 7-year property overstates the recovery period by two years.
• Qualified improvement property is “any improvement made by the taxpayer to an interior portion of a building which is nonresidential real property” placed in service after the building was, per 168(e)(6), excluding enlargements, elevators and structural framework. A new operatory carved out of existing space qualifies; a new wing doesn’t.
• Section 179 is elected asset by asset on Form 4562 and can be revoked on an amended return; bonus applies automatically unless you elect out of a whole class. Bonus can create a net operating loss, which is why a start-up practice with a loss in year one uses bonus rather than 179. The mechanics, the trade-in trap and the S-corp basis point are in the Section 179 versus bonus guide for construction equipment; the rules are identical for a dental chair.
• California allows Section 179 of only $25,000, phased out above $200,000 of purchases, and doesn’t conform to 168(k) at all (FTB Form 3885 instructions). A California practice that expenses a $175,000 CBCT under bonus gets nothing on the state return in year one and depreciates it over five years for California; putting $25,000 of it under 179 first salvages that much.

Are dental supplies an expense or inventory?

An expense, in the year they’re used, and for a cash-basis practice that’s the year they’re bought. Under Reg. 1.162-3, materials and supplies are deductible when “first used in the taxpayer’s operations or are consumed,” and anything with “an economic useful life of 12 months or less” or a cost “of $200 or less” is a material or supply by definition. Gloves, composites, cements and anesthetic cartridges are all consumed within weeks.

• Practices under the gross receipts test never have to keep an inventory count. IRC 471(c) lets a taxpayer meeting the 448(c) test ($31,000,000 for 2025, $32,000,000 for 2026 under Rev. Proc. 2024-40 and 2025-32) treat inventory “as non-incidental materials and supplies,” deductible as used, with no beginning and ending inventory.
• Bigger-ticket consumables still qualify. Implant bodies and abutments at $150 to $500 a unit, and handpieces up to $2,500, come under the de minimis safe harbor in Reg. 1.263(a)-1(f), which the IRS sets at “$2,500 per invoice or item for taxpayers without applicable financial statements” (IRS tangible property FAQ). The election is an annual statement on the return; miss it and a $2,400 handpiece is technically a depreciable asset.
• Track supplies by category anyway. Clinical disposables, implant components, aligner or ortho materials and in-house milling blocks in separate accounts is what lets you explain a supplies line that jumped 60% in a year when implant volume doubled.

How are lab fees, CE, insurance and professional fees deducted?

All as ordinary and necessary expenses under 162(a), with timing set by your accounting method and a few specific rules. A cash-basis practice deducts a lab invoice when it’s paid (Reg. 1.461-1(a)(1)); an accrual practice deducts it when the lab delivers, since economic performance for services occurs “as such person provides such services” under IRC 461(h).

• Malpractice, general liability, workers’ comp, cyber and property premiums are deductible on the same basis; the premium lines are covered in the dental insurance guide.
• Continuing education is deductible if it “maintains or improves skills required by the individual in his employment or other trade or business” under Reg. 1.162-5. An implant placement course, a sedation permit program or an aligner certification keeps a licensed dentist inside dentistry; the “new trade or business” bar that blocks a career change doesn’t reach them. Travel and lodging for the course are deductible, meals at 50% under IRC 274(n), and the family’s extra days at the resort aren’t.
• Staff CE, OSHA and bloodborne-pathogen training, CPR certification and expanded-function training are the practice’s expense when the practice pays.
• The owner’s own health insurance follows the entity. A sole proprietor or partner deducts it on the personal return under IRC 162(l); an S-corp owner runs it through the W-2 and deducts it the same way. Life insurance is the exception: IRC 264(a)(1) allows no deduction for “premiums on any life insurance policy … if the taxpayer is directly or indirectly a beneficiary,” which catches key-person and buy-sell coverage.
• Accounting, legal, payroll and consulting fees are deductible, with one carve-out: fees “to facilitate” buying a practice must be capitalized under Reg. 1.263(a)-5 into the purchase price rather than deducted, which the valuation and sale guide covers from both sides.

What about rent, technology and marketing?

Deductible, with the related-party lease as the one line that needs a file behind it. IRC 162(a)(3) allows “rentals or other payments required to be made as a condition to the continued use or possession” of property you don’t own, and when the landlord is the dentist’s own LLC the rent has to be a market rate. Rent above market is disguised compensation on exam, disallowed on the practice side while still taxed on the landlord side. A broker opinion or appraisal when the lease is set, refreshed every few years, closes that question.

• Subscription software (practice management, imaging, patient communication, claims clearinghouse, cloud backup) is a current expense when paid. A purchased perpetual license is depreciated straight-line over “a useful life of 36 months” under IRC 167(f)(1), or expensed under 179 or bonus. Hardware is 5-year property and expensed the same way as any other equipment.
• Marketing is advertising expense with no special limit: website, SEO, pay-per-click, social, direct mail, sponsorships, referral credits and directory listings. A website with real back-end functionality (a patient portal, online payments) may need to be capitalized as software rather than expensed, so ask the developer to split the invoice.
• HIPAA compliance, from the risk assessment to encryption and an outside compliance service, is an ordinary cost of running a healthcare business.
• Utilities, common-area charges and pass-through property taxes under a triple-net lease are all deductible as paid.

Are start-up costs before the practice opens deductible?

Not the way operating costs are. Anything spent before the first patient, including rent during build-out, staff hired and trained early, market studies and pre-opening marketing, is a start-up expenditure under IRC 195. You deduct “the lesser of … the amount of start-up expenditures … or $5,000, reduced (but not below zero) by the amount by which such start-up expenditures exceed $50,000,” and “the remainder … ratably over the 180-month period beginning with the month in which the active trade or business begins.”

• Spend $70,000 getting a scratch start ready and the $5,000 allowance is gone (it phases out fully at $55,000); the whole $70,000 amortizes at about $4,667 a year from the opening month.
• Equipment and build-out bought before opening aren’t start-up costs; they’re capital assets placed in service on opening day and expensed under 179 or bonus that year.
• Buying an existing practice changes the analysis, because the purchase price is allocated to assets under IRC 1060 and the deal costs are capitalized. The start-up costs guide works through both routes.

What deductions get missed most often?

Merchant fees, patient-financing discounts, regulated waste, the home office, mileage and the timing of bad debt. Each is fully deductible and each gets lost for the same reason: it never appears as its own number.

• Card processing fees run 2% to 3% of card volume. On $1,000,000 of collections that’s $20,000 to $30,000 a year, deductible under 162 whether or not you book it, but only visible if you report gross collections as revenue and the fee as an expense.
• Patient-financing platforms charge the practice a discount, commonly 5% to 14% of the financed amount. Finance $200,000 of treatment at an average 8% and you paid $16,000; it’s deductible and it isn’t the same line as card fees.
• Regulated waste. The EPA’s dental rule in 40 CFR Part 441 “applies to dental dischargers,” with exemptions only for practices that “exclusively practice” oral pathology, radiology, oral surgery, orthodontics, periodontics or prosthodontics. The separator, its filters, the amalgam recycling and the sharps contract are all deductible compliance costs.
• Home office. A dentist doing charts and bookkeeping from a room used “exclusively … on a regular basis” for the business under IRC 280A can use the simplified method in Rev. Proc. 2013-13: “the prescribed rate is $5.00” per square foot, “not to exceed 300 square feet,” so $1,500 at most. For an S-corp owner it runs through an accountable-plan reimbursement from the company.
• Mileage between the practice, the lab, the hospital and CE. The IRS business rate is 70 cents a mile for 2025, 72.5 cents for January to June 2026 and 76 cents for July to December 2026 (IRS standard mileage rates). Commuting from home to the office isn’t deductible.
• Bad debt. An accrual practice deducts a patient balance that “becomes worthless within the taxable year” under IRC 166. A cash-basis practice never recognized the income, so there’s nothing to deduct; writing the balance off the books is bookkeeping only.
• Dues, licenses and DEA registration are deductible by the practice. If associates are W-2 employees, have the practice pay their dues; since 2018 they can’t deduct unreimbursed professional expenses on their own returns.

What should I do next?

Pull last year’s return and the chart of accounts side by side and look for the four missing lines. Then check the fixed asset schedule: anything sitting on a 7-year life that’s a chair, an imaging unit or a handpiece is class 57.0 and 5-year, and anything expensed federally needs its own California or other-state schedule if you file there. If you opened in the last three years, confirm the start-up amortization actually started in the opening month.

• The equipment decision feeds the S-corp salary and the retirement plan in the same year: dental practice entity structure and dental practice retirement plans.
• The overhead benchmarks these deductions roll up into: dental practice bookkeeping and overhead.
• Whether the hygienist on a daily rate is really a contractor: dental hygienist classification.
• The same deduction map for law firms and franchise owners, and what happens if a deduction is challenged: the accuracy-related penalty and reasonable cause.

Related guides:

• Dental Equipment Depreciation: Section 179, Bonus Depreciation, and What to Expense First

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.