Section 179 vs. Bonus Depreciation: Which Tax Strategy Saves You More?

What Is Section 179?

Section 179 of the IRS tax code allows businesses to deduct the full purchase price of qualifying equipment or software in the year it is placed into service, rather than depreciating it over multiple years. Think of it as an immediate expensing election. Congress created it specifically to encourage small and mid-sized businesses to invest in equipment and technology.

For the 2025 tax year, the key limits are:

• Maximum deduction: $1,220,000
• Phase-out threshold: $3,050,000 (the deduction reduces dollar-for-dollar above this point)
• Taxable income cap: You cannot deduct more than your net business taxable income—the excess carries forward to next year

What qualifies? Most tangible personal property used in business—machinery, equipment, computers, software, office furniture, and certain vehicles. Many improvements to non-residential real property (HVAC, roofing, security systems) also qualify under Section 179. What doesn't qualify: buildings themselves, land, and property used outside the U.S.

The key mechanic: Section 179 is an election. You choose how much to deduct—up to the full cost of each asset, or a partial amount. This gives you precise control over your taxable income. If you want to deduct exactly $80,000 to drop into a lower tax bracket, you can do exactly that.

What Is Bonus Depreciation?

Bonus depreciation (technically the “additional first-year depreciation deduction” under IRC Section 168(k)) is a separate provision that allows businesses to immediately deduct a percentage of the cost of qualifying assets. Unlike Section 179, bonus depreciation applies automatically unless you affirmatively opt out on IRS Form 4562.

The Tax Cuts and Jobs Act of 2017 raised bonus depreciation to 100% through 2022. Since then, it has been phasing down:

• 2022: 100%
• 2023: 80%
• 2024: 60%
• 2025: 40%
• 2026: 20%
• 2027 and beyond: 0% (unless Congress extends it)

Qualifying property includes most depreciable business assets with a recovery period of 20 years or less. Critically, bonus depreciation has no taxable income limitation. It can create a net operating loss (NOL) that you carry forward to future years—a powerful tool in high-investment years.

Section 179 vs. Bonus Depreciation: Side-by-Side

Here is how the two provisions stack up across the most important dimensions for business owners making equipment decisions:

Real-World Examples With Real Numbers

Let's run the numbers on a business owner in the 32% tax bracket who purchases $100,000 of qualifying equipment in 2025 with $150,000 in net income before the deduction.

Option A: Section 179 Only

• Section 179 deduction: $100,000 (full cost, within taxable income limit)
• Taxable income after deduction: $50,000
• Tax savings at 32%: $32,000

Option B: Bonus Depreciation Only (40% in 2025)

• Bonus depreciation deduction (40%): $40,000
• Standard depreciation on remaining $60,000 over 5 years: approximately $12,000 in year one
• Total year-one deduction: approximately $52,000
• Tax savings year one at 32%: approximately $16,640

The $300K Scenario: Where Combining Strategies Pays Off

Now imagine the same owner buys $300,000 of equipment with only $150,000 in taxable income. Section 179 alone is capped at $150,000 (the income limitation). The optimal move: apply Section 179 to $150,000, then apply 40% bonus depreciation to the remaining $150,000 basis—capturing an additional $60,000 deduction in year one. Total year-one deduction: $210,000. Tax savings at 32%: approximately $67,200. The NOL created by bonus depreciation carries forward to offset next year's income.

The Special Vehicle Rules

Vehicles are where business owners most often get tripped up. The IRS imposes “luxury auto” limits on passenger vehicles (under 6,000 lbs GVWR), regardless of whether you use Section 179 or bonus depreciation. For 2025, the first-year cap on passenger vehicles is approximately $12,400 with bonus depreciation—even if you paid $60,000 for the vehicle.

The workaround most contractors already know: SUVs and trucks over 6,000 lbs GVWR are not subject to luxury auto limits. A Ford F-250, Ram 2500, or Chevy Silverado 2500 used for business can be fully expensed under Section 179 or receive full bonus depreciation treatment. This is why so many contractors drive heavy-duty pickups—the tax math is very real.

When to Use Section 179 vs. Bonus Depreciation

Use Section 179 When:

• You want precise control over your taxable income (e.g., staying below a bracket threshold or QBI phase-out)
• You have enough taxable income to absorb the full deduction this year
• You want to apply the deduction to specific assets and not all of them
• You're buying used equipment and want maximum flexibility in the deduction amount

Use Bonus Depreciation When:

• Your equipment purchases exceed your taxable income and you want to create an NOL to carry forward
• You're in a very profitable year and want to eliminate as much taxable income as possible
• You're buying property that qualifies for bonus but not Section 179 (e.g., certain qualified improvement property)
• You want the deduction to apply automatically without making a specific election on each asset

Use Both When:

• Your purchases exceed what Section 179 can absorb within your taxable income limit
• You want to maximize year-one deductions while retaining carryforward flexibility
• You're executing a planned year-end tax strategy across multiple asset classes

How to Combine Both for Maximum Savings

The optimal approach for most businesses with significant equipment purchases is to apply Section 179 first, up to the income limitation, then apply bonus depreciation to any remaining basis. Here's the step-by-step process:

1. Calculate your expected net business income for the year before any equipment deductions
2. Apply Section 179 up to that income amount to avoid the carryforward limitation
3. Apply 40% bonus depreciation to the remaining cost basis of qualifying assets
4. Standard depreciation handles whatever is left over the asset recovery period (typically 5 or 7 years)
5. Any NOL created by bonus depreciation carries forward indefinitely to offset future income at full value

The key is planning this before year-end, not after. Most of the benefit is lost when business owners wait until their CPA asks in February what equipment they bought last year. By then, the opportunity to time the purchase strategically has passed. See our guide to proactive tax planning for how to structure a full-year approach to equipment strategy.

Industry Examples: Contractors and Dentists

General Contractor: $275K Equipment Year

A roofing contractor with $200,000 in net profit buys a new enclosed trailer ($45K), a skid steer ($110K), and service trucks ($120K total, all GVWR over 6,000 lbs). Total investment: $275,000. Strategy: Apply Section 179 to $200,000 (income cap), apply 40% bonus depreciation to the remaining $75,000 cost basis ($30,000 additional deduction). Total year-one deduction: $230,000. Tax savings at 32%: approximately $73,600. Without strategic planning, they would have deducted only a small fraction of this in year one. For more, see our guide to contractor tax deductions.

Dental Practice: $200K Imaging Equipment

A dentist with $350,000 in net income purchases a cone beam CT scanner for $200,000. Section 179 covers the full $200,000 (well within both the income cap and the $1.22M annual limit). At a 37% effective rate, that's a $74,000 reduction in taxes—enough to offset nearly 40% of the purchase price through tax savings alone. See the full breakdown of dental equipment tax strategy for your practice.

Whether you're a contractor making heavy equipment purchases or a professional services firm investing in technology, the strategy is the same: understand your income, know your limits, and plan your purchases intentionally. That's the difference between a reactive tax filer and a business owner who treats taxes as a strategic lever. If you're not sure you're using these tools correctly, our $10K tax savings guarantee is a good place to start the conversation.

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