The IRS assigns your building one of two default recovery periods: 27.5 years or 39 years. That classification sets how much of your building's cost you deduct each year. It is only the starting point, though, because individual components inside the building can depreciate far faster.

Most investors know their property depreciates. Fewer understand how much the recovery period matters, or how cost segregation can accelerate the timeline for both residential and commercial owners.

This article compares the two recovery periods side by side. You will see the dollar impact of each schedule, learn which one applies to your property, and understand how cost segregation changes the math.

Key Takeaways

• Residential rental property depreciates over 27.5 years; nonresidential (commercial) property over 39 years, both straight-line under the General Depreciation System (IRS Publication 946).
• On the same $1,640,000 depreciable basis after an 18% land allocation, the 27.5-year schedule produces about $17,585 more depreciation per year than the 39-year schedule.
• Depreciation is a cash benefit only if you can use the loss. Rental losses are generally passive and may be suspended unless you have passive income to offset, qualify as a real estate professional, or meet the short-term rental material-participation rules (IRS Topic No. 425). Even a nonpassive loss may be capped by the §461(l) excess business loss limitation.
• A whole-house or condo short-term rental operated for transient stays is generally treated as 39-year nonresidential property, but the transient-use test applies at the establishment level and can be less clear for one STR unit inside an otherwise long-term rental building (IRS Publication 527).
• Cost segregation reclassifies components into 5-, 7-, and 15-year property. Under the One Big Beautiful Bill Act, qualified property acquired and placed in service after January 19, 2025 can claim 100% bonus depreciation; property acquired under a binding contract before January 20, 2025 stays on the prior phase-down by placed-in-service year — 40% in 2025 and 20% in 2026 (IRS).
• Depreciation is recaptured at sale: 5- and 7-year property is generally recaptured as ordinary income under §1245, while 15-year land improvements and the building are §1250 property; depreciation above straight line is ordinary income and the balance may be unrecaptured §1250 gain taxed at up to 25% (IRS Topic No. 409).

The Basics: What Is Depreciation?

Depreciation is a non-cash tax deduction. It lets you recover the cost of your investment property over time, even though you did not spend cash this year.

The IRS sets the timeline. Residential rental property depreciates over 27.5 years. Nonresidential (commercial) property depreciates over 39 years. Both use the straight-line method under the General Depreciation System (IRS Publication 946). Taxpayers that make the real property trade or business election under §163(j) generally use the Alternative Depreciation System instead, with 30-year residential and 40-year nonresidential recovery periods. The deduction is level across the middle years, but the mid-month convention prorates your first and final years. A 27.5-year asset actually spans 28 tax years, and a 39-year asset spans 40.

One rule holds in every case: land is never depreciable. Only the building and its components count toward your depreciable basis, so getting your land value allocation right matters. Note that land improvements such as paving and landscaping are depreciable as separate 15-year property; raw land is not.

Here is a simple example. You buy a property for $1,000,000 and allocate 18%, or $180,000, to land. Your depreciable basis is $820,000.

• At 27.5 years: $820,000 ÷ 27.5 = about $29,818 per year
• At 39 years: $820,000 ÷ 39 = about $21,026 per year

That is about an $8,793 annual difference on the same purchase price. Over a full 10-year hold, the residential owner deducts roughly $87,925 more. These are illustrative full-year figures; your first year is prorated under the mid-month convention.

27.5-Year Depreciation: Residential Rental Property

The 27.5-year schedule applies to residential rental property. The IRS defines this as any building for which 80% or more of gross rental income comes from dwelling units (IRC Section 168(e)(2)).

Properties that typically qualify:

• Single-family rentals
• Duplexes and triplexes
• Apartment buildings
• Condominiums rented long-term

How the math works:

Take a residential rental purchased for $1,000,000 with 18%, or $180,000, allocated to land. The depreciable basis is $820,000.

$820,000 ÷ 27.5 = about $29,818 per year in straight-line depreciation.

At a 37% marginal rate, that deduction is worth about $11,033 a year. It helps only an investor who can actually use it. Rental losses are generally passive, so they may be suspended unless you have passive income to offset or you qualify for Real Estate Professional Status or meet the short-term rental material-participation rules (IRS Topic No. 425). Even when the loss is nonpassive, the §461(l) excess business loss limitation caps aggregate business losses at roughly $256,000 for a single filer or $512,000 for a joint return in 2026; the excess becomes a net operating loss carryforward.

Why does my short-term rental show 39 years instead of 27.5 years?

Your short-term rental is generally classified as 39-year nonresidential real property under the "transient use" rule. IRS Publication 527 states that residential rental property "doesn't include a unit in a hotel, motel, inn, or other establishment where more than half of the units are used on a transient basis."

Practitioners often use stays of less than 30 days as the transient-use benchmark because former Treasury Regulation §1.167(k)-3(c)(1) defined transient occupancy that way. It is not a standalone bright-line test under §168(e)(2), so confirm your classification with your CPA. The statutory test applies at the establishment level: a whole house or condo operated nightly or weekly is generally a transient establishment, but one STR unit inside a building whose other units are leased long-term is less clear because more than half of the establishment's units must be used transiently.

Because STR owners are stuck with the slower 39-year base schedule, cost segregation becomes even more valuable. The reclassified 5-, 7-, and 15-year components use the same recovery periods whether the building itself is residential or nonresidential. A study can typically reclassify roughly 25–40% of a commercial or STR property's components into those faster categories. These are typical ranges we see, and actual results depend on the property. The STR loophole can add further tax advantages when you materially participate.

39-Year Depreciation: Commercial and Nonresidential Property

The 39-year schedule applies to nonresidential real property. This includes any building that does not meet the 80% residential income test.

Properties that qualify:

• Office buildings
• Retail spaces
• Warehouses and industrial properties
• Hotels, which are treated as commercial
• Short-term rentals with average stays of 30 days or fewer
• Mixed-use properties where less than 80% of income is residential
• Self-storage facilities

How the math works:

Use the same values. A commercial building bought for $1,000,000 with 18%, or $180,000, allocated to land has a depreciable basis of $820,000.

$820,000 ÷ 39 = about $21,026 per year in straight-line depreciation.

At 37%, that deduction is worth about $7,779 a year for an investor who can use it.

Compare the two: $11,033 versus $7,779. On the same basis, the 39-year owner sees about $3,253 less in annual deduction value. Over a 10-year hold, that gap reaches roughly $32,532. Commercial and short-term rental owners feel the slower recovery more acutely, which is why cost segregation matters for these properties.

Side-by-Side Comparison: The Dollar Impact

Here is the full picture on a $2,000,000 property with an 18%, or $360,000, land allocation and a $1,640,000 depreciable basis.

After 10 years, the 27.5-year schedule produces about $175,851 more in depreciation than the 39-year schedule on the same basis. For an investor who can fully use the deductions at a 37% rate, that is about $65,065 in additional tax value. These figures are illustrative: Year 1 is prorated under the mid-month convention, and the actual benefit depends on your ability to use the losses.

How Cost Segregation Changes Both Scenarios

A cost segregation study reclassifies building components from the default 27.5- or 39-year schedule into 5-, 7-, and 15-year asset recovery periods. Under the One Big Beautiful Bill Act, qualified property acquired and placed in service after January 19, 2025 qualifies for 100% bonus depreciation, so eligible reclassified components can be deducted in full in Year 1 (IRS). Property acquired under a binding contract before January 20, 2025 remains on the prior phase-down based on its placed-in-service year — 40% in 2025 and 20% in 2026 — even if it is placed in service after January 19, 2025. See the Big Beautiful Bill update for how the return of 100% bonus depreciation affects your planning.

Residential example:

Take a $2,000,000 apartment building with an 18% land allocation and a $1,640,000 depreciable basis. A study reclassifies $410,000, or 25%, into accelerated categories. With 100% bonus depreciation, the investor deducts $410,000 in Year 1, versus about $59,636 under standard depreciation. At 37%, the reclassified amount represents about $151,700 in first-year deduction value, assuming the components are bonus-eligible and the investor can use the loss.

Commercial example:

Take a $2,000,000 office building with the same $1,640,000 basis. A study reclassifies $492,000, or 30%. Commercial buildings often reclassify a higher share because they contain more specialty electrical, plumbing, and mechanical systems. With 100% bonus depreciation, that is a $492,000 Year 1 deduction, versus about $42,051 under standard depreciation. At 37%, the reclassified amount represents about $182,040 in first-year deduction value.

The key insight is that cost segregation narrows the gap between residential and commercial. Reclassified components follow the same 5-, 7-, and 15-year schedules regardless of building type, so the default schedule matters less once a meaningful share of your building depreciates on an accelerated timeline.

Does cost segregation work better for residential or commercial properties?

Both benefit. Commercial properties often reclassify 25–40% of basis. Residential properties typically see 20–35%. These are typical ranges we see, and actual results depend on the property and a detailed study. The cost segregation ROI is usually strong for either category.

Don't Forget Recapture

When you sell, the depreciation you claimed is subject to recapture. Five- and 7-year personal property reclassified in a cost segregation study is generally recaptured as ordinary income under §1245. Fifteen-year land improvements and the building are §1250 property: depreciation above straight line is ordinary income, while the balance may be unrecaptured §1250 gain taxed at a federal rate of up to 25% (IRS Topic No. 409). Factor recapture into your hold-and-sell strategy. A 1031 exchange can defer these taxes when you reinvest.

How to Determine Your Property's Classification

The IRS uses the 80% gross rental income test.

• If 80% or more of the building's gross rental income comes from dwelling units, it is residential rental property, depreciated over 27.5 years.
• If less than 80% comes from dwelling units, it is nonresidential, depreciated over 39 years.

Key considerations:

• A mixed-use building with ground-floor retail and upper-floor apartments can fall on either side, depending on the income split. The test is applied each year, and the fair rental value of a dwelling unit occupied by the owner is counted as dwelling-unit rental income for the 80% test.
• Hotels and establishments where more than half of the units are used transiently are treated as nonresidential, even though guests stay there. Practitioners often use stays of less than 30 days as the transient benchmark, but classification depends on the establishment-level facts.
• If a mixed-use building crosses the 80% threshold, the change-in-use rules apply to the remaining basis. A move to a longer recovery period generally applies prospectively; a move to a shorter period is available only by election.
• Correcting a prior depreciation classification follows the two-return rule. If only one return has been filed using the old method, generally amend it. Once two or more consecutive returns use that method, file Form 3115 to make the change and claim any §481(a) catch-up adjustment.

Not sure where your property lands? Your CPA can confirm the classification.

The Bottom Line

The recovery period the IRS assigns is only the starting point. A cost segregation study, paired with bonus depreciation, can move a significant share of your building onto a much faster timeline. The benefit is largest when you can use the deductions in the year you claim them.

Curious how much of your property could qualify for accelerated depreciation? See how much you could save with R.E. Cost Seg.

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