MACRS Depreciation: Classes, Conventions, and Section 179

MACRS depreciation, short for the Modified Accelerated Cost Recovery System, is the method the tax code requires for writing off the cost of most business property placed in service after 1986. Instead of deducting the full price of a machine, vehicle, or building the year you buy it, MACRS spreads the deduction across a set number of years under Section 168 of the Internal Revenue Code, usually with larger write-offs early on.¹ Two first-year provisions, Section 179 and bonus depreciation, can override the schedule and let you deduct all or part of the cost immediately.

What Property Qualifies

An asset has to meet four tests before it goes through MACRS at all:²

You own the property, or bear its economic benefits and burdens.
You use it in a trade or business, or hold it to produce income.
It has a determinable useful life (it wears out, decays, or becomes obsolete).
That useful life extends beyond one year.

Land fails the third test and is never depreciable. Intangible assets like franchises, trademarks, and goodwill aren’t run through MACRS either; they’re amortized over 15 years under Section 197.³

For low-cost items, you can skip depreciation entirely. The de minimis safe harbor election lets you immediately expense tangible property costing $2,500 or less per item, or $5,000 if your business has audited financial statements.⁴ A $400 printer and a $1,200 desk go straight on the return without a depreciation schedule.

Recovery Period Classes

Every MACRS asset is assigned to a class that fixes the number of years over which you recover its cost. The common ones:²

3-year: specialized tools, over-the-road tractor units, certain short-lived manufacturing equipment.
5-year: automobiles, light trucks, computers, copiers, and appliances. This is the class most small businesses use most.⁵
7-year: office furniture and fixtures, agricultural machinery, and any asset without an assigned class life.
15-year: land improvements like fences, roads, and shrubbery, plus qualified improvement property (interior work on nonresidential buildings placed in service after 2017).
20-year: municipal sewers and certain farm buildings.
27.5-year: residential rental buildings and their structural components.
39-year: nonresidential real property, meaning commercial buildings like offices, warehouses, and retail space.

Classification matters. Putting an asset in the wrong class changes every year’s deduction and can trigger an adjustment on audit.

GDS or ADS

MACRS has two sub-systems. The General Depreciation System (GDS) is the default and uses the shorter recovery periods above with accelerated methods, producing bigger early-year deductions. The Alternative Depreciation System (ADS) uses longer periods and straight-line only, spreading smaller deductions over more years.

ADS is mandatory in a handful of situations:⁵

Property used predominantly outside the United States.
Property financed with tax-exempt bonds.
Property used by tax-exempt organizations.
Property held by an electing real property trade or business or electing farming business that opted out of the Section 163(j) interest limitation.

Under ADS, residential rental stretches from 27.5 to 30 years, nonresidential real from 39 to 40 years, and personal property without a class life uses 12 years.¹ You can also elect ADS voluntarily, but the election covers every asset in the same class placed in service that year (real property is elected property-by-property), and it’s generally irrevocable.

Conventions: When the Clock Starts

MACRS uses timing rules called conventions to decide how much depreciation you claim in the first and last years.

Half-year: the default for most personal property. The asset is treated as placed in service at midyear regardless of the actual date, so you get half a year in year one and half a year in the final year.²
Mid-month: applies to all real property. Depreciation starts at the midpoint of the month the building is placed in service.
Mid-quarter: kicks in when more than 40% of your total personal-property basis for the year is placed in service in the fourth quarter. When it triggers, every asset placed in service that year uses the midpoint of its own quarter instead of midyear.

The mid-quarter rule exists to stop businesses from stockpiling assets in December and grabbing a half year of depreciation for a few weeks of use. If you’re planning a big late-year purchase, check whether it will pull you past 40% and shrink first-year deductions on everything else you bought.

Depreciation Methods

Once you have the class and the convention, one of three methods calculates the annual deduction:

200% declining balance: the most aggressive, and the default for 3-, 5-, 7-, and 10-year property under GDS.
150% declining balance: used for 15- and 20-year property under GDS.
Straight-line: required for all real property (27.5-year and 39-year) and for everything under ADS.

With either declining balance method, the calculation automatically switches to straight-line the year that straight-line yields an equal or larger deduction, so the full cost is recovered by the end of the period.²

A quick example. Buy $1,000 of 5-year property in February, no mid-quarter trigger, 200% declining balance. The rate is 200% ÷ 5 = 40%. Year one, the half-year convention halves it: $1,000 × 40% ÷ 2 = $200. Year two, basis drops to $800 and the full 40% applies: $320. Each following year, reduce the basis by the prior year’s depreciation and reapply the rate until straight-line wins. In practice, most filers skip the arithmetic and use the percentage tables in IRS Publication 946, which bake in the convention and the method switch.

Section 179 and Bonus Depreciation

Two provisions can override the annual schedule and put a big deduction, or the whole cost, in year one.

Section 179

Section 179 lets you elect to expense the full cost of qualifying business property in the year it’s placed in service, subject to annual caps. For tax years beginning in 2026, the maximum deduction is $2,560,000, and it phases out dollar-for-dollar once you place more than $4,090,000 of qualifying property in service. SUVs have their own $32,000 cap on the Section 179 deduction.⁶

Section 179 can’t take you below zero. The deduction is limited to your business’s taxable income for the year, and any unused amount carries forward. That makes it less useful in a loss year.

Bonus Depreciation

Bonus depreciation under Section 168(k) is an additional first-year deduction on top of, or in place of, regular MACRS. The One, Big, Beautiful Bill Act signed in 2025 set bonus depreciation permanently at 100% for qualifying property acquired after January 19, 2025.⁷ Qualifying property must have a MACRS recovery period of 20 years or less, which covers most equipment, vehicles (subject to the passenger auto caps below), and other personal property, new or used.

Property acquired before January 20, 2025, but placed in service during 2026 stays on the old phase-down schedule at 20%.⁸ The acquisition date, not the placed-in-service date, controls the rate. Unlike Section 179, bonus depreciation has no dollar cap and can create or enlarge a net operating loss.

You can also elect a smaller bonus rate. For property placed in service in the first tax year ending after January 19, 2025, you can choose 40% instead of 100%, or 60% for property with longer production periods.⁷ That can make sense if you expect higher rates in future years.

One state-tax caveat: many states decouple from federal bonus depreciation and require a separate calculation on the state return. Your federal write-off may not reduce your state bill the same way.

Vehicles and Listed Property

Passenger automobiles get special treatment because they’re easy to use personally. Section 280F caps annual depreciation regardless of the car’s price. For vehicles placed in service in 2026:⁸

With bonus depreciation: $20,300 year one, $19,800 year two, $11,900 year three, and $7,160 each year after until fully recovered.
Without bonus depreciation: $12,300 year one, $19,800 year two, $11,900 year three, and $7,160 each subsequent year.

The caps mean a $60,000 car takes far longer than five years to fully depreciate. Heavy SUVs and trucks over 6,000 pounds gross vehicle weight are exempt from the Section 280F caps, though they still hit the $32,000 Section 179 SUV limit; bonus depreciation applies to the rest of the cost.⁶

Vehicles and certain other property prone to personal use are “listed property.” If business use is 50% or less, you can’t use accelerated methods or bonus depreciation at all; you’re locked into straight-line over the ADS recovery period.⁹ Worse, if business use drops below 50% in a later year after you’ve already claimed accelerated deductions, you have to recapture the excess as ordinary income on Form 4797. This catches taxpayers who claim big first-year vehicle deductions and then shift the car mostly to personal use.

Recapture When You Sell

Every depreciation deduction reduces your tax basis in the asset. Sell the asset for more than that reduced basis and the IRS recaptures the prior write-offs by taxing gain at ordinary rates rather than the lower capital gains rate.

For personal property (equipment, vehicles, machinery), Section 1245 treats the gain as ordinary income to the extent of all depreciation previously claimed. Buy a $50,000 machine, depreciate it to $10,000, sell for $35,000: the entire $25,000 gain is ordinary income.¹⁰

Real property uses Section 1250. Because buildings depreciate straight-line, there’s usually no “additional depreciation” to recapture as ordinary income. Instead, gain up to the amount of prior straight-line depreciation is “unrecaptured Section 1250 gain,” taxed at a maximum 25% rate. Any remaining gain is taxed at capital gains rates.¹¹

Recapture is the hidden cost of aggressive depreciation. Bigger early deductions mean a larger recapture hit at sale. For assets you’ll hold a long time, the trade often still works because you keep the time value of the earlier deductions. For assets you plan to flip, run the numbers first.

How to Report It

MACRS deductions, Section 179 elections, bonus depreciation, and listed-property information all go on Form 4562, Depreciation and Amortization, attached to your business return (Schedule C, partnership, S corporation, or corporate).¹² When you sell or dispose of a depreciated asset, the sale and any recapture go on Form 4797, Sales of Business Property.¹³ Keep the placed-in-service date, cost basis, recovery period, and accumulated depreciation for every asset; you’ll need all of it to complete both forms and to defend the numbers if the return is examined.

1
Office of the Law Revision Counsel. 26 USC 168 – Accelerated Cost Recovery System
2
Internal Revenue Service. Publication 946 – How To Depreciate Property
3
Office of the Law Revision Counsel. 26 US Code 197 – Amortization of Goodwill and Certain Other Intangibles
4
Internal Revenue Service. Notice 2015-82 – Increase in De Minimis Safe Harbor Limit
5
Internal Revenue Service. Publication 527 – Residential Rental Property
6
Internal Revenue Service. Rev. Proc. 2025-32
7
Internal Revenue Service. Treasury, IRS Issue Guidance on the Additional First Year Depreciation Deduction Amended as Part of the One Big Beautiful Bill
8
Internal Revenue Service. Rev. Proc. 2026-15
9
Internal Revenue Service. Instructions for Form 4562 – Depreciation and Amortization
10
Office of the Law Revision Counsel. 26 USC 1245 – Gain From Dispositions of Certain Depreciable Property
11
Office of the Law Revision Counsel. 26 USC 1250 – Gain From Dispositions of Certain Depreciable Realty
12
Internal Revenue Service. About Form 4562, Depreciation and Amortization
13
Internal Revenue Service. About Form 4797, Sales of Business Property