What MACRS depreciation is, and what the acronym leaves unsaid

The acronym is on every depreciation schedule printed in the United States and almost never spelled
out on any of them. It appears as a column heading, or compressed into a method cell alongside a
life and a convention, and the software applies it without ever explaining what it is.

MACRS stands for the Modified Accelerated Cost Recovery System. It is the system that determines
how the cost of business property is recovered for federal tax purposes — how much of an asset's
cost becomes a deduction in each year after it is placed in service.

Both adjectives in the name are doing work, and neither is decoration. Something was modified, and
something is accelerated. Knowing what, in each case, explains most of what a schedule looks like.

What was modified, and what came before

The Accelerated Cost Recovery System arrived with the Economic Recovery Tax Act of 1981. It replaced
a regime in which depreciation ran over an asset's estimated useful life, argued asset by asset
against facts and circumstances, and it substituted fixed statutory recovery periods instead. Less
judgment, more table.

MACRS is what the Tax Reform Act of 1986 made of it, and it governs property placed in service after
1986. ACRS still applies to property placed in service between 1981 and 1986 — which is why a
long-lived asset base can carry rows under a system that stopped taking new entrants four decades
ago, and why import formats still enumerate ACRS method codes alongside the MACRS ones.

The practical shape of the modification: MACRS lengthened several recovery periods relative to ACRS,
reworked the class structure, and set out the conventions and methods in a form that a table can
express completely. The result is a system where, given a handful of facts about an asset, the
annual deduction follows without further argument.

The four facts the system runs on

MACRS produces a number from a small, fixed set of inputs, plus the date the property was placed in
service:

• The property class, which fixes the recovery period. Publication 946 assigns assets to classes; the general depreciation system runs 3, 5, 7, 10, 15, 20 and 25 years for personal property, 27.5 years for residential rental property, and 39 years for nonresidential real property placed in service after the relevant date.
• The method — 200% declining balance, 150% declining balance, or straight line.
• The convention — half-year, mid-quarter or mid-month, which governs how much of the first and final years count.
• The basis for depreciation, limited to business or investment use.

Everything a schedule prints in its depreciation columns follows from those. Nothing else about the
asset enters the computation — not what it is called, not what it is worth now, not what it was
bought for in relation to what it will fetch later.

That last point is worth stating on its own, because it is the sharpest difference between MACRS and
the depreciation an accountant books for management purposes.

What MACRS deliberately ignores

Salvage value. Under MACRS, property is recovered to zero. There is no residual, no estimate of
what the asset will be worth at the end, and no reduction of the depreciable base to account for
one. Book depreciation frequently does the opposite, running straight line over an estimated useful
life down to an estimated salvage value.

This is why a book schedule and a tax schedule for the same asset disagree, often substantially, and
why a report headed "Book" will not reconcile to a return. It is a legitimate document answering a
different question.

Actual useful life. The recovery period comes from a class, not from an engineering judgment
about how long the asset will last. Equipment that will plainly run for twenty years may be
recovered over seven; a building that will stand for a century is recovered over 39.

When in the year it was bought, beyond what the convention captures. The half-year convention
treats everything placed in service that year as placed in service at the midpoint, whether it
arrived in January or December.

Accelerated, and what that means arithmetically

The declining balance methods take a larger deduction in the early years than straight line would,
and a smaller one later. The total recovered over the full period is the same; only its distribution
across years changes.

Under 200% declining balance, the annual rate is twice the straight-line rate applied to the
remaining undepreciated basis. Because that produces an ever-smaller deduction, MACRS switches to
straight line for the remaining basis at the point where straight line yields more — which is why
the published percentage tables have that characteristic shape, rising to a peak in year two and
then falling away unevenly.

The 15- and 20-year classes use 150% declining balance rather than 200%. Real property uses straight
line throughout; there is no acceleration on a building.

GDS and ADS — two systems inside the acronym

MACRS contains two systems, and a schedule will not always tell you which one a row is on.

The general depreciation system is the default, and it is what most rows use. The alternative
depreciation system uses straight line over generally longer recovery periods. ADS is mandatory in
specific circumstances — listed property used 50% or less in a qualified business use, tax-exempt
use property, property used predominantly outside the United States, certain farming property — and
it is available by election otherwise. The election, once made for a class of property in a year, is
irrevocable.

On the return, the distinction is visible: Section B of Part III of
Form 4562 reports GDS additions and Section C reports ADS ones, in
separate blocks. On a printed depreciation schedule it is often only inferable from the life — a
straight-line row with an unusually long recovery period against its class is the usual tell.

Where §179 and bonus sit relative to all this

They sit outside MACRS and run before it.

§179 expensing and the special depreciation allowance — bonus — are separate provisions that reduce
the basis MACRS then recovers. An asset that took §179, then bonus on what remained, enters the
MACRS computation with whatever basis is left, and the schedule's depreciation columns work on that
reduced figure.

That ordering is the reason prior §179 and prior bonus matter so much when a client's asset base
moves between software, and why a schedule that folds all three into one combined prior depreciation
figure is a genuine loss rather than a formatting quirk. The consequences of that specific case are
in what Lacerte's summary schedule leaves out.

How MACRS shows up on a page

In a method column, and rarely in full. 200DB, 150DB, SL, MACRS, M200, or all three facts
compressed into one cell as something like 5 HY 200DB — five-year recovery, half-year convention,
200% declining balance.

Reading those cells, and knowing which columns a given suite prints and which it silently omits, is
a separate skill from understanding the system, and it is the one that decides whether an asset base
can be moved without re-keying it. That is covered in
reading a MACRS depreciation schedule, along with what the
percentage tables look like and why a five-year asset sits on the schedule for six years.

If the reason you are asking is that a schedule from a prior preparer has landed on your desk, the
practical question is not really what MACRS is — it is what that particular document does and does
not carry. The prior year depreciation schedule page
is about that.

FAQ

What does MACRS stand for?

Modified Accelerated Cost Recovery System. It is the federal tax depreciation system for property
placed in service after 1986, introduced by the Tax Reform Act of 1986.

What is MACRS depreciation?

The recovery of a business asset's cost as a deduction over a statutory period, determined by the
asset's property class, the depreciation method, the convention, and the basis. It replaced a system
based on estimated useful life with one based on fixed classes and published percentage tables.

What did MACRS modify?

The Accelerated Cost Recovery System of 1981, which it revised in 1986 — lengthening several
recovery periods, reworking the class structure, and setting the methods and conventions in their
current form. ACRS still governs property placed in service between 1981 and 1986.

Does MACRS use salvage value?

No. Property is recovered to zero under MACRS, with no residual value subtracted from the
depreciable base. Book or management depreciation commonly does subtract one, which is why the two
schedules for the same asset do not agree.

What is the difference between GDS and ADS?

The general depreciation system is the default and uses declining-balance methods for the shorter
classes. The alternative depreciation system uses straight line over generally longer recovery
periods, and is required for certain categories of property such as listed property used 50% or less
in a qualified business use, and available by election otherwise.

Why is MACRS called accelerated?

Because the declining-balance methods deduct more in the early years of the recovery period than
straight line would, and less later. The total recovered is unchanged; only the timing differs. Real
property is on straight line and is not accelerated in this sense.