Section 179 vs Bonus Depreciation for Professional Practice Equipment (Dental, Medical, Vet, Med Spa)

Disclaimer: The information on this website (including all examples, explanations, and content) is for general informational purposes only and should not be considered tax, legal, or financial advice. The specific limits and percentages for Section 179 and bonus depreciation change every year through tax legislation. Always check the current IRS rules and consult with a qualified professional about your specific situation.

"Should I Use Section 179 or Bonus Depreciation on the New Laser?"

This is one of the most common questions I get from dental, medical, veterinary, and med spa practice owners. Equipment is expensive, the tax code offers two different ways to accelerate the deduction, and the owner usually wants to know which one to use before signing the purchase agreement.

The honest answer: usually both, in a specific order, with a few facts that decide which one matters. The two methods overlap significantly, and for most equipment purchases by most practices, the practical decision is which method gets used first to get to the full deduction, not which one is "better" in some abstract sense.

This guide walks through what each method is, how they interact, and the questions you actually need to answer before deciding. It is not a comprehensive treatment of every depreciation rule. It covers the common cases for professional practice equipment.

For the official IRS rules, Publication 946 on depreciating property is the authoritative source.

What Section 179 Is

Section 179 is a provision in the tax code that lets a business deduct the full cost of qualifying property (equipment, certain software, qualified improvement property) in the year it is placed in service, rather than depreciating it over the property's useful life.

What Qualifies

Tangible personal property used in the business (most equipment qualifies)
Off the shelf computer software
Qualified improvement property (certain non residential building improvements)
Vehicles, with specific weight class rules
Certain large SUVs with their own dollar cap

The Limits

Section 179 has two important dollar limits that change annually:

Annual deduction cap: the maximum amount of Section 179 deduction the business can take in a year (currently in the hundreds of thousands of dollars, but check the current IRS Publication 946 for the exact number for the year in question)
Property phase out threshold: the amount of total qualifying property placed in service above which the Section 179 deduction starts to phase out dollar for dollar
Business income limitation: Section 179 cannot create a net loss for the business. The deduction is limited to taxable income from the active trade or business. Any disallowed amount carries forward to future years.

Section 179 Cannot Create a Loss

This is the most important practical limit. If your practice has $200,000 of net income before considering equipment depreciation, and you place $400,000 of equipment in service, the Section 179 deduction is limited to $200,000 (with the remaining $200,000 of basis carried forward to future years or eligible for bonus depreciation in the current year).

For practice owners buying significant equipment in a year when income is otherwise modest, this limit can be the difference between two strategies.

What Bonus Depreciation Is

Bonus depreciation is a separate provision that allows a percentage of the cost of qualifying property to be deducted in the year placed in service.

What Qualifies

Tangible personal property with a recovery period of 20 years or less (most equipment qualifies)
Qualified improvement property
Most software

The Bonus Percentage Changes

The bonus depreciation percentage has been the moving target in this area of tax law. It has been 100% in some years, 50% in others, 80%, 60%, 40%. Recent and pending tax legislation has changed the schedule multiple times.

Always check the IRS Publication 946 for the bonus depreciation percentage in effect for the specific year the property is placed in service. A percentage from a prior year cannot be relied on for the current year.

Bonus Depreciation Can Create a Loss

Unlike Section 179, bonus depreciation can create a net operating loss for the business. That loss can then carry forward to offset income in future years (with specific rules about carry forward periods and limits).

For owners buying large equipment in a year when income is modest, bonus depreciation can produce a current year loss that shelters future year income. This is one of the situations where bonus depreciation has an advantage over Section 179.

How They Interact

For most equipment purchases, both methods are available. The practical approach is usually:

Apply Section 179 first up to the annual limit (or to the business income limit if income is the binding constraint)
Apply bonus depreciation to whatever basis remains after Section 179
Apply regular MACRS depreciation to whatever basis remains after both of the above (often $0 for most equipment purchases by small practices)

This sequence produces the maximum first year deduction in most cases. For practices that benefit from creating a current year loss, the order can be flipped (skip Section 179 entirely, apply bonus depreciation, accept the loss).

When Section 179 Wins

The practice has strong current year income and wants to maximize the current year deduction
The equipment purchase is below the Section 179 annual cap
The owner does not want or need a current year net operating loss

When Bonus Depreciation Wins

The practice has modest current year income and would benefit from a net operating loss that offsets future years
The equipment purchase exceeds the Section 179 annual cap
The equipment does not qualify for Section 179 but qualifies for bonus depreciation (rare, but it happens)

When You Use Both

The total equipment purchase exceeds the Section 179 annual cap
The practice wants to maximize current year deduction up to the income limit, then use bonus depreciation for the rest

Practical Examples for Different Practice Types

These are illustrative scenarios, not specific recommendations. The right approach depends on the practice's actual income, the actual equipment purchase, and the current year limits.

Dental Practice Buying a Cone Beam CT Scanner

Cone beam CTs are common large dental equipment purchases. They typically qualify for both Section 179 and bonus depreciation. For a practice with strong income, Section 179 to the cap with the remainder under bonus depreciation generally produces the largest first year deduction.

Medical Practice Upgrading an EHR System and Adding Imaging

EHR systems are often software (different rules), and imaging equipment is tangible personal property. The software side may qualify for Section 179 (off the shelf software does). The imaging equipment qualifies for both Section 179 and bonus depreciation. The practical approach is to coordinate the deduction across the entire purchase.

Veterinary Practice Adding Digital Radiography

Digital radiography conversions are a common large equipment purchase for vet practices. Both Section 179 and bonus depreciation typically apply. The decision often comes down to current year income and whether the practice wants to create a net operating loss to carry forward.

Med Spa Buying a New Laser Platform

Laser platforms are typically expensive enough to be a meaningful tax decision. Both Section 179 and bonus depreciation typically apply. For a profitable spa, the order is usually Section 179 first to the cap or income limit, then bonus depreciation on the remainder. For a newer spa that is not yet profitable, bonus depreciation alone can produce a useful loss to carry forward.

Special Vehicle Rules

Vehicles have their own rules and are one of the most commonly misunderstood pieces of this area of tax law.

Passenger Vehicles

Passenger vehicles (cars and SUVs under 6,000 pounds gross vehicle weight) are subject to specific annual depreciation caps that limit the Section 179 and bonus depreciation amounts regardless of the vehicle's cost. The caps change annually.

Heavy Vehicles (Over 6,000 Pounds GVWR)

SUVs and trucks with gross vehicle weight over 6,000 pounds are subject to a different (higher) Section 179 cap. This is the "G wagon loophole" you see referenced in business owner forums. The cap is higher but not unlimited.

Vehicles Over 14,000 Pounds GVWR

Larger trucks (over 14,000 pounds GVWR) typically qualify for full Section 179 and bonus depreciation without the passenger vehicle limits. This is more relevant for ambulatory veterinary practice trucks than for typical professional practice vehicles.

The vehicle rules are nuanced enough that they should be reviewed with your tax advisor before the purchase, not after.

Business Income Limitation in Detail

The Section 179 business income limitation deserves more attention because it is the most commonly missed planning point.

How It Works

Section 179 deduction cannot exceed the taxable income from the active trade or business in which the property is used. The calculation includes:

Net income from the business itself (before considering the Section 179 deduction)
W-2 wages from any active trade or business of the taxpayer or spouse (when filing jointly)
Other active trade or business income

It does not include passive income, portfolio income, or capital gains.

Why It Matters for High Equipment Years

If a dentist buys $300,000 of equipment in a year when the practice's net income before depreciation is only $250,000, the Section 179 deduction is limited to $250,000. The remaining $50,000 of basis is either:

Eligible for bonus depreciation in the current year (if bonus depreciation percentage is high enough)
Carried forward as Section 179 to future years
Depreciated over the remaining MACRS recovery period

The interaction between Section 179, bonus depreciation, and the business income limitation can produce different results depending on the order in which methods are applied. This is the planning that your tax advisor should be doing for you when a large equipment purchase is in the works.

Spousal W-2 Wages Can Help

If the practice owner's spouse has W-2 wages from active employment, those wages count toward the Section 179 business income limitation on a joint return. For high earner couples filing jointly, this can effectively raise the practical Section 179 limit.

Timing the Purchase

When you place the equipment in service matters as much as the dollar amount.

Placed in Service vs Purchased

The deduction is based on when the equipment is placed in service, not when you pay for it. Equipment ordered and paid for in December but not delivered and installed until February is a next year purchase for tax purposes.

For year end equipment purchases, the practical test is whether the equipment is delivered, installed, and ready for use by December 31. A leased delivery time in January moves the deduction to the following year.

Financing and Leasing

How you finance the equipment generally does not affect the Section 179 or bonus depreciation deduction. Cash purchase, equipment financing, capital lease all produce the same depreciation result.

Operating leases are different. An operating lease is treated as rent, deductible as paid, with no depreciation deduction. Whether a transaction is a capital lease or an operating lease depends on the specific lease terms.

Coordinating With Year End Income

If your tax advisor projects that the practice will have particularly strong income in a given year, accelerating an equipment purchase into that year can produce a larger deduction at a higher marginal rate. Conversely, if the practice expects strong income in the following year, delaying the purchase may produce a deduction at a higher marginal rate next year.

This kind of multi year planning is one of the practical benefits of working with a tax advisor who reviews your practice's projections, not just last year's books.

Common Mistakes With Section 179 and Bonus Depreciation

These are the recurring ones I see:

Using last year's Section 179 cap and bonus depreciation percentage for this year's planning. The numbers change. Check current IRS Publication 946.

Assuming Section 179 can create a loss. It cannot. The business income limitation applies. If the limitation matters, bonus depreciation is the alternative.

Buying equipment in December and assuming the deduction applies to that year. Placed in service matters, not paid for. December 30 invoice with January 5 installation is a January deduction.

Treating an operating lease like a capital lease. Operating leases deduct as rent, not depreciation.

Forgetting the passenger vehicle caps. A $90,000 SUV is not a $90,000 first year deduction. The caps apply.

Missing the qualified improvement property option. Build out improvements (interior, non structural improvements to non residential buildings) can sometimes qualify for accelerated depreciation. This is worth asking your tax advisor about for build out years.

Frequently Asked Questions

What is the Section 179 limit for this year?

Check IRS Publication 946 for the current year limit. The number changes through tax legislation.

What is the bonus depreciation percentage for this year?

Same answer. Check IRS Publication 946 for the current year percentage. The schedule has been changing under recent tax legislation.

Can I take both Section 179 and bonus depreciation on the same piece of equipment?

Yes, with the same sequence I described earlier. Section 179 first up to the cap or income limit, bonus depreciation on whatever basis remains, regular depreciation on whatever is left after that.

What if the equipment is partly business and partly personal?

Both Section 179 and bonus depreciation require the equipment to be used more than 50% for business. Below 50% business use, neither applies. The deduction is based on the business use percentage.

What if I lease the equipment?

Capital leases are typically treated like a purchase for depreciation purposes. Operating leases are typically treated like rent (deducted as paid). The classification depends on the specific lease terms. Your tax advisor reviews the lease.

Do I have to choose one method?

No. The methods are not mutually exclusive. Most practices use both, applied in a specific sequence that produces the largest current year deduction.

What if my practice has a loss this year?

Section 179 cannot create or increase a loss. Bonus depreciation can. If you want a loss to carry forward, bonus depreciation is the option.

Getting Equipment Depreciation Right

Equipment purchases are some of the largest single tax decisions a practice owner makes. The interaction between Section 179, bonus depreciation, and the business income limitation is nuanced enough that the difference between a well planned purchase and a poorly planned purchase can be tens of thousands of dollars in current year tax.

The right time to think about this is before you sign the purchase agreement, not after. A 10 minute conversation with your tax advisor before the purchase often saves more tax than the equipment financing structure does.

This decision pairs naturally with broader year end tax planning. Our year end tax planning guide covers the December moves Section 179 and bonus depreciation fit into, and our quarterly estimated taxes for high income professionals post covers how a large Q4 equipment purchase changes the Q4 estimate calculation.

We work with dental, medical, veterinary, med spa, pharmacy, and other professional practice owners across Quinlan, Hunt County, Rockwall, Kaufman, and the greater Dallas area on tax planning that includes equipment purchase timing, depreciation method selection, and the broader year end tax projections that go with running a practice.

Planning a major equipment purchase? Contact us here to talk through the depreciation strategy before you sign.