Section 179 vs Bonus Depreciation: 5 Essential Rules for 2026

Section 179 vs Bonus Depreciation: Why 2026 Is the Best Year to Get This Right

Section 179 vs bonus depreciation is one of the most practical conversations your CPA firm can have with a business client right now. At BusAcTa Advisors, we support CPA firms across the US with tax preparation and advisory work, and we have seen both rules dramatically change in 2026 thanks to the One Big Beautiful Bill Act (OBBBA), signed into law on July 4, 2025. The combination of a $2.56 million Section 179 cap and permanently restored 100 percent bonus depreciation means almost every equipment purchase a small or mid-size business makes this year can be fully deducted in year one.

That's a genuine planning opportunity. But it only works if you and your clients understand how the two rules differ, when to use each one, and where the traps are. This guide explains both rules in plain language, compares them side by side, and gives your firm the talking points to make this conversation count on every business return.

This article is general information, not tax advice for a specific situation. Clients should work with a qualified tax professional before making capital purchase decisions based on tax treatment.

What Section 179 Actually Does

Section 179 of the Internal Revenue Code lets a business deduct the full purchase price of qualifying property in the year it is placed in service, instead of depreciating it over five, seven, or fifteen years under the standard MACRS schedule. The deduction is elective. Your client chooses which assets to apply it to, asset by asset, on Form 4562.

For tax year 2026, the key numbers are:

• Maximum deduction: $2,560,000 (up from $1,250,000 before OBBBA)

• Phase-out threshold: $4,090,000 of total qualifying property placed in service

• Phase-out mechanic: the deduction reduces dollar for dollar above the threshold, reaching zero at $6,650,000

• Heavy SUV cap: $32,000 for vehicles with a gross vehicle weight rating over 6,000 pounds

Section 179 qualifying property includes most depreciable tangible personal property: machinery, equipment, computers, off-the-shelf software, certain vehicles, and qualified improvement property for nonresidential real estate (roofs, HVAC, fire protection systems, security systems). The building structure itself does not qualify.

There's one hard limit your clients need to understand. Section 179 cannot exceed the taxpayer's active trade or business taxable income for the year. A business running a loss cannot use Section 179 to deepen that loss. Any unused Section 179 carries forward to future years indefinitely, but it doesn't help the client in the current year if income isn't there.

Section 179 is a precision tool. Your client picks the assets, controls the deduction amount, and stays within their taxable income. That makes it ideal for managing profitability in a profitable year.

What Bonus Depreciation Does, and How OBBBA Changed It

Bonus depreciation under IRC Section 168(k) is a first-year additional depreciation allowance applied automatically to qualifying assets, unless the taxpayer elects out. Before the OBBBA, the bonus rate had been phasing down from 100 percent (2017 to 2022) to 80 percent in 2023, 60 percent in 2024, and was scheduled to fall to 40 percent in 2025 and 20 percent in 2026, before disappearing entirely in 2027.

The OBBBA reversed all of that. Bonus depreciation is restored to 100 percent permanently for qualifying property acquired and placed in service after January 19, 2025. There is no scheduled phasedown anymore. A business that buys $3 million of qualifying equipment in 2026 can deduct the entire $3 million in year one.

What qualifies? The asset categories are similar to Section 179: tangible personal property with a recovery period of 20 years or less, qualified improvement property for nonresidential real estate, certain vehicles, computers, and commercially available software. Bonus depreciation also applies to used property, as long as it is new to the purchasing business and was not acquired from a related party.

The critical difference from Section 179: bonus depreciation has no taxable income limitation. It can create or deepen a net operating loss (NOL). For a client who had a rough year but still invested in equipment, bonus depreciation may be the better tool because it generates an NOL that carries forward to profitable years.

Bonus depreciation is a blunt instrument, but in the best possible way. No dollar cap, no income limit, and now permanently at 100 percent. For large equipment purchases, it often produces a bigger immediate benefit than Section 179 alone.

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

Your clients will ask which one to use. The honest answer is usually both, applied in the right order. But they need to understand the key differences first.

IRS rules require Section 179 to be applied first, then bonus depreciation covers any remaining basis. That ordering matters for your calculations on Form 4562.

When to Use Section 179, When to Use Bonus, and When to Use Both

In our experience working with CPA firms on business returns, three questions drive the strategy on each asset purchase.

Does the client have taxable income this year? If yes, Section 179 makes sense because it can absorb that income with a controlled, elective deduction. If the client is already at a loss or break-even, bonus depreciation generates the NOL that carries forward, which often produces a larger long-term benefit.

How much is the client spending on equipment? Below the $4,090,000 phase-out threshold, Section 179 is fully available. Above it, the Section 179 deduction shrinks dollar for dollar. Above $6,650,000, Section 179 disappears entirely and bonus depreciation does the heavy lifting with no comparable cap.

What does your client's state tax situation look like? This is the most commonly overlooked issue. Many states do not fully conform to federal bonus depreciation rules. A client who takes 100 percent federal bonus depreciation on a $500,000 machine may still need to depreciate that same asset over seven years on their state return. Section 179 conformity varies by state too, but generally more states conform to Section 179 than to federal bonus depreciation. Your firm needs to run both calculations before advising clients in states with partial or non-conforming rules.

Here's how three common client scenarios play out in 2026:

• Profitable consulting firm, $120,000 in new computers and servers: Elect Section 179 on all assets. Full deduction in year one, no carryforward needed, straightforward Form 4562 filing.

• Manufacturing company, $4,500,000 in new equipment: The phase-out reduces Section 179 to $1,650,000. Apply Section 179 to selected assets first, then bonus depreciation covers the rest. Full first-year deduction still achievable.

• Startup with no taxable income, $200,000 in equipment: Section 179 is unusable because there's no income to absorb it. Bonus depreciation creates a $200,000 NOL that carries forward to profitable years.

What Qualifies and What Doesn't: Common Client Misconceptions

Your clients will overestimate what qualifies. These are the boundaries your firm needs to set clearly on every engagement.

Vehicles are complicated. Passenger automobiles with a gross vehicle weight rating under 6,000 pounds face luxury auto limits under IRC Section 280F. The first-year cap for such vehicles is approximately $20,400 in 2026 even when bonus depreciation applies. Heavy SUVs and trucks over 6,000 pounds have no luxury auto cap, but Section 179 is limited to $32,000 for this category. The vehicle must be used more than 50 percent for business, and your client needs mileage logs to prove it.

Building structures never qualify. Neither Section 179 nor bonus depreciation covers the structural components of a building. What does qualify is qualified improvement property (QIP): interior improvements to nonresidential buildings placed in service after the building was originally placed in service. Roofs, HVAC, fire protection, and security systems on nonresidential property also qualify under Section 179.

The asset must be placed in service, not just purchased. A client who buys equipment in December but doesn't install or put it to use until January of the following year cannot claim the deduction in the purchase year. Placed-in-service date controls everything.

Property used less than 50 percent for business doesn't qualify for bonus depreciation. Your client with a vehicle used 45 percent for business gets regular MACRS depreciation on the business-use portion, nothing more.

How Your Offshore Tax Preparation Team Handles This

Depreciation strategy is your firm's advisory call. But the mechanics of Form 4562, coordinating Section 179 elections with bonus depreciation, running state conformity adjustments, and tracking the placed-in-service dates across a client's asset list, that's the preparation work that eats your team's time during busy season.

BusAcTa's offshore tax preparation team handles exactly that layer. Our preparers are fluent in US GAAP depreciation rules and work in your existing software, including QuickBooks, Xero, and NetSuite for the underlying asset data, and your tax platform for the return itself. Your firm's reviewer signs off before anything reaches the client. That division of labor means your licensed staff spend their time on the strategic question, which assets, which method, which year, rather than on the mechanical calculation.

For clients with complex asset schedules across multiple states, our virtual CFO support can also help model the multi-year impact of different depreciation elections before the client commits to a purchase timeline. And for firms building out their capacity to handle more business returns, our build your team model gives you a dedicated named preparer who learns your practice's standards and carries them season to season.

In our view, the biggest mistake CPA firms make on depreciation is treating it as a compliance task rather than a planning conversation. The client who bought $800,000 of equipment without asking you first could have timed that purchase to save $150,000 in tax. That conversation is where your firm earns its relationship.

Conclusion and Next Steps

Section 179 vs bonus depreciation in 2026 isn't really a competition. Both rules work together, with Section 179 giving your clients precision and control over selected assets, and bonus depreciation handling the rest automatically with no dollar cap and no income floor. The OBBBA made both more generous than they have been in years, and for most small and mid-size business clients, a well-planned equipment purchase is now fully deductible in year one.

The firms that get the most value from these rules are the ones that have the conversation before the client signs the equipment lease or wires the deposit, not after. Build that prompt into your business tax intake, and you'll find depreciation planning becomes one of your most appreciated advisory services.

If your firm wants support handling the Form 4562 mechanics and multi-state depreciation adjustments across your business client base, schedule a scoping call with BusAcTa Advisors. We will show you exactly how our offshore preparation team supports your reviewers, so your licensed staff can focus on the strategy that keeps clients coming back.