Bonus depreciation and accelerated depreciation both recover an asset’s cost faster than a straight-line schedule, but they do it differently. Bonus depreciation lets you deduct 100% of a qualifying asset’s cost in the year you place it in service. Accelerated depreciation, meaning the declining-balance methods built into MACRS, front-loads deductions across the asset’s recovery period without collapsing them into a single year. The choice between them is really a choice about timing, flexibility, and what your tax picture looks like beyond the current return.
The Core Mechanical Difference
Both methods live inside the Modified Accelerated Cost Recovery System, the required framework for most tangible business property placed in service after 1986.1Legal Information Institute. MACRS MACRS assigns every depreciable asset to a class life: 3, 5, 7, 10, 15, or 20 years for personal property, longer for real estate. Straight-line depreciation spreads the cost evenly across that period. Anything faster is a form of acceleration.
Bonus depreciation is acceleration taken to its limit. You deduct the full cost immediately and the asset carries a zero basis for the rest of its useful life. Accelerated MACRS uses a declining-balance formula: a higher-than-straight-line rate applied to the asset’s shrinking book value each year, producing bigger deductions early and smaller ones later. Over the full recovery period both methods and straight-line all recover the same total cost. Only bonus depreciation compresses that recovery into a single year.
How Bonus Depreciation Works Now
For qualifying property acquired after January 19, 2025, bonus depreciation is a permanent 100% first-year deduction under the One, Big, Beautiful Bill Act, signed July 4, 2025.2Internal Revenue Service. Treasury, IRS Issue Guidance on the Additional First Year Depreciation Deduction Amended as Part of the One Big Beautiful Bill There is no scheduled phase-down.
Eligible property includes tangible MACRS assets with a recovery period of 20 years or less, off-the-shelf computer software, and qualified improvement property (interior improvements to a nonresidential building). Both new and used assets qualify, provided the used property wasn’t previously used by you or bought from a related party.3Internal Revenue Service. Additional First Year Depreciation Deduction (Bonus) – FAQ Buildings and structural components don’t qualify.
The deduction is automatic. Place a qualifying asset in service and 100% bonus applies unless you affirmatively elect out on your return, and that election covers every asset in the same property class placed in service that year. You report the deduction on Form 4562.4Internal Revenue Service. About Form 4562, Depreciation and Amortization There is no dollar cap and no income limitation, so bonus depreciation can create or deepen a net operating loss.
One boundary worth flagging: the OBBBA is not retroactive. Property placed in service in 2023 or 2024 stays under the old TCJA phase-down (80% and 60%, respectively), and you cannot amend a prior return to claim the full 100%.
How Accelerated MACRS Works
The default MACRS method for 3-, 5-, 7-, and 10-year property is 200% declining balance. You take double the straight-line rate and apply it to the asset’s remaining book value each year. Five-year property has a 20% straight-line rate, so the declining-balance rate is 40%.5Office of the Law Revision Counsel. 26 U.S. Code 168 – Accelerated Cost Recovery System Year one applies 40% to full cost (adjusted by the half-year convention, so effectively 20%). Year two applies 40% to whatever’s left. Because the rate hits a shrinking balance, the dollar deduction naturally falls each year.
The code requires a switch from declining balance to straight-line in the first year that straight-line on the remaining basis would produce a larger deduction. That switch is baked into the IRS tables and guarantees full cost recovery by the end of the period.
For 15- and 20-year property, MACRS mandates the gentler 150% declining balance method. Owners of shorter-lived property can elect 150% as well if they want less aggressive front-loading than the 200% default.
What Accelerated MACRS Won’t Do
Real property is excluded. Nonresidential buildings depreciate straight-line over 39 years, residential rental over 27.5 years, and neither qualifies for declining-balance methods or for bonus depreciation. Interior improvements to nonresidential buildings can qualify as QIP, which carries a 15-year life and is eligible for 100% bonus.
Where Section 179 Fits In
Section 179 is a third first-year write-off tool that often gets folded into the same conversation. For 2026, the maximum Section 179 deduction is $2,560,000, phasing out dollar-for-dollar once total qualifying property placed in service exceeds $4,090,000.6Office of the Law Revision Counsel. 26 USC 179 – Election to Expense Certain Depreciable Business Assets
Two features distinguish Section 179 from bonus depreciation. First, the deduction cannot exceed your active trade or business taxable income for the year; any excess carries forward.7eCFR. 26 CFR 1.179-2 – Limitations on Amount Subject to Section 179 Election Bonus depreciation has no such cap. Second, Section 179 is asset-by-asset: you pick which items to expense and how much of each cost to write off. Bonus depreciation is all-or-nothing by property class.
You can use all three on the same purchase. Section 179 applies first, bonus depreciation next, and any remaining basis enters the regular MACRS tables. Each layer reduces the basis available to the next, so the ordering matters when you’re modeling the numbers.
Vehicles: Where the Bonus Advantage Shrinks
Section 280F caps annual depreciation on passenger automobiles regardless of which method you’re using. For vehicles placed in service in 2026:8Internal Revenue Service. Revenue Procedure 2026-15
- Year 1 with bonus: $20,300; without bonus: $12,300
- Year 2: $19,800
- Year 3: $11,900
- Each following year: $7,160
The practical bonus benefit on a passenger vehicle is the $8,000 first-year gap. Any basis left over after the recovery period continues at $7,160 per year until fully recovered or the vehicle is disposed of.9Office of the Law Revision Counsel. 26 USC 280F – Limitation on Depreciation for Luxury Automobiles Vehicles with a gross weight rating over 6,000 pounds sit outside the passenger-automobile definition and escape these limits, which is why heavy SUVs and trucks stay popular business purchases.
State Conformity Can Flip the Calculus
Federal and state depreciation often diverge. Roughly 15 states fully conform to federal bonus depreciation, and a handful offer their own full expensing. The rest either decouple from bonus depreciation or conform to an older version of the Internal Revenue Code that predates the OBBBA. In non-conforming states you add the federal bonus deduction back on the state return and run standard MACRS instead, meaning you maintain two depreciation schedules.
The 200% and 150% declining-balance methods draw far less state resistance because they’ve been permanent code for decades. For a multi-state business, that compliance simplicity can tip the choice toward accelerated MACRS even when bonus depreciation would produce a bigger federal deduction.
Recapture on Sale
Every dollar of depreciation reduces adjusted basis. When you sell, Section 1245 recaptures the gain attributable to prior depreciation as ordinary income, taxed at your regular rate rather than at capital gains rates.10Office of the Law Revision Counsel. 26 U.S. Code 1245 – Gain From Dispositions of Certain Depreciable Property
Bonus depreciation makes this bite hardest. Buy equipment for $100,000, claim 100% bonus, sell three years later for $40,000, and the entire $40,000 is ordinary-income recapture. Under 200% declining balance, basis would still be positive at year three and the recapture on the same sale would be smaller. The upfront deduction is larger with bonus; the back-end tax is larger too. Whether that trade works out depends on your rates in each year and the value of deferring tax in between.
Choosing Between Them
Bonus depreciation is the most aggressive option and produces the largest present-value benefit. It fits a business with a high-income year, especially a one-time spike, that wants to shelter as much as possible now. The cost is that you’ve used the whole deduction in year one. If income drops next year, this asset offers nothing more.
Accelerated MACRS is the middle path. Deductions are still front-loaded but taper across the recovery period, which is easier to model against multi-year forecasts. For a business with steadily growing income, or one that wants meaningful early deductions without the cliff, the 200% declining-balance curve is often the better fit.
Section 179 solves a different problem: selective expensing with an income guardrail. You pick which assets to write off and by how much, and the deduction can’t push you into a loss on your active business income. It works well when you want to expense some purchases immediately and depreciate others normally.
Layering is common. On one asset you might take Section 179 on part of the cost, bonus depreciation on the remainder, and standard MACRS on anything left. The ordering is fixed, but within it you have room to shape the deduction profile to match how you expect income, state conformity, and eventual disposition to play out.