At a glance
- What a study costs. An engineered study with a site inspection generally runs $3,000 to $4,000. A virtual study, appropriate for smaller residential properties, is usually $1,000 or less.
- What it returns. On a $750,000 single-family rental, reallocating roughly 22% of the building to shorter-lived property moves about $127,000 of depreciation into year one.
- The catch nobody leads with. A study does not create a deduction. It accelerates one, and the passive activity rules decide whether you can use it this year at all.
- Bonus depreciation is back at 100% and permanent for qualified property acquired and placed in service after January 19, 2025, which is what makes a study worth running again.
A cost segregation study is an engineering analysis that breaks a building into its components so the parts with shorter tax lives can be depreciated over 5, 7 or 15 years instead of 27.5. On rental property the arithmetic is usually favorable and occasionally dramatic. Whether it is worth it for you turns on three things: what the study costs, how much of your building reallocates, and whether the tax rules let you use the deduction in the year you take it.
That third question is the one most writing on this subject skips, and it is the one that decides the answer. This page covers all three, with the prices we charge and the arithmetic written out.
What a cost segregation study actually does
When you buy a rental property, the default treatment puts the entire building on a 27.5-year straight-line schedule for residential rental property, or 39 years for nonresidential real property. Land is never depreciable and comes out first.
A study takes that single building figure apart. An engineer identifies the components that are properly personal property or land improvements rather than structure: appliances, carpeting, cabinetry, specialty electrical, window treatments, driveways, walkways, fencing and landscaping tied to improvements. Those reclassified components carry recovery periods of 5, 7 or 15 years under MACRS, and because they are section 1245 property rather than structure, they also qualify for bonus depreciation.
The IRS publishes its own examiner guidance on how these studies should be conducted, in the Cost Segregation Audit Techniques Guide. It is worth knowing that document exists, because it is the standard a study is judged against if anyone asks.
What this looks like on an actual return
If you read nothing else, read this. Same property, same year, with and without a study.
A single-family rental bought for $750,000 and placed in service in 2026. Figures are illustrative and rounded, and the land allocation is shown as its own line because land never depreciates.
| On the return | Without a study | With a study |
|---|---|---|
| Purchase price | $750,000 | $750,000 |
| Land, not depreciable | $150,000 | $150,000 |
| Building, 27.5-year | $600,000 | $468,000 |
| 5-year personal property | — | $78,000 |
| 15-year land improvements | — | $54,000 |
| Bonus depreciation, first year | — | $132,000 |
| Building depreciation, first full year | $21,818 | $17,018 |
| First-year depreciation | $21,818 | $149,018 |
About $127,200 more depreciation in year one, on identical facts. For an investor at a 35% marginal rate that is roughly $44,500 of tax deferred, against a study costing $3,000 to $4,000. The first-year building figure ignores the mid-month convention, which reduces it slightly in the year of purchase.
The one-line version. A study does not create a deduction. It moves deductions forward, and you pay for the timing. Figures are illustrative.
What a cost segregation study costs
Prices in this market are quoted privately more often than they are published — which makes the question hard to research, and easy to be overcharged on. Ours, for what it is worth, are these.
| What | Who you pay | Typical cost |
|---|---|---|
| Engineered study with a site inspection The thorough version, for larger or more complex properties. |
Specialist study firm | $3,000–$4,000 |
| Virtual study, no site visit Appropriate for smaller properties, roughly $300,000 and under. |
Specialist study firm | $1,000 or less |
| Applying the study on your return Including the depreciation schedules and the passive activity analysis. |
Us | $1,500–$2,000 |
We do not perform studies and we do not take referral fees for them. Study quality varies considerably, and a weak study is a liability rather than an asset, because it is the document that has to hold up if anyone asks. What we will do is tell you which kind your property warrants and who does credible work.
When a study is worth it, and when it is not
The arithmetic is favorable at a surprisingly low purchase price. On the example above the study pays for itself many times over in year one. The real question is not whether the deduction is larger. It is whether you can use it.
Rental losses are passive by default under section 469, which means they offset passive income and nothing else. They sit and wait — until you have passive income, or until you sell. A $127,000 acceleration that lands in the suspended-loss column is not worth $44,500 this year; it is worth $44,500 at some point, which is a different proposition against a fee due now.
There are three ways the loss becomes usable, and they are the whole decision:
- The average stay is short. If the average guest stay is seven days or fewer, the activity is not a rental for the passive loss rules, and a material participation test decides the rest. This is the route most owners of an Airbnb or Vrbo property take.
- Real estate professional status. More than half your working time and over 750 hours in real property trades or businesses, plus material participation. The bar is genuinely high, and the 750-hour rule is where most claims fail.
- You have passive income to shelter. Other profitable rentals, or income from activities you do not materially participate in.
If none of those describe you, a study still helps, because shorter-lived property depreciates faster in every later year too. It simply does not produce the first-year result the marketing promises, and it should be priced against a slower benefit.
One more ceiling sits above all of it. Even where the loss is not passive, section 461(l) caps how much business loss can offset other income. For 2026 the threshold is $256,000, or $512,000 on a joint return, per Rev. Proc. 2025-32. Anything above that carries forward as a net operating loss rather than sheltering this year’s wages.
The 2026 rules that change the arithmetic
Two things moved recently, and both matter to this decision.
Bonus depreciation is back at 100% and permanent. Public Law 119-21 reinstated the full first-year allowance for qualified property acquired and placed in service after January 19, 2025. During the phase-down, a study reclassifying $132,000 would have produced a fraction of that in year one. At 100% it produces all of it, which is the single largest reason studies are worth running again. Our guide to cost segregation and bonus depreciation covers how the two work together, since they are not alternatives.
You can now elect a lower percentage. Notice 2026-11, issued in January 2026, lets a taxpayer elect 40% instead of 100% for property placed in service during the first tax year ending after January 19, 2025. That sounds like a concession nobody would take — and for most people it is. It matters when a full first-year deduction would be wasted: suspended by the passive rules, stranded above the section 461(l) cap, or simply larger than the income it could shelter. Electing down converts a deduction you cannot use into depreciation spread over years you can.
Residential rental property and single-family homes
Studies are often discussed as though they were a commercial-property exercise. They are not. Residential rental property runs on a 27.5-year life against 39 for nonresidential, so the gap between the default schedule and the reclassified components is wider, not narrower, and the reallocation percentages on a furnished single-family rental are frequently better than on an office building.
What changes with a smaller residential property is the economics of the study itself — not the tax. Below roughly $300,000 of building basis, a virtual study is usually the right instrument, and the fee should reflect that. Paying $4,000 for an engineered study on a $250,000 condominium is how the exercise stops being worth it.
Short-term rentals are the strongest case of all, because the passive problem largely disappears. We cover that combination in detail in cost segregation for Airbnb, and the qualification tests in the short-term rental strategy.
A study on a property you already own
You are not limited to the year of purchase. A property held for several years can still have a study performed, and the depreciation you should have taken is recovered without amending a single return.
The mechanism is a change in method of accounting on Form 3115, with a section 481(a) adjustment that captures the cumulative difference between the old schedule and the new one. A favorable adjustment is taken entirely in the year of change: the instructions state that “the section 481(a) adjustment period is generally 1 tax year (year of change) for a negative section 481(a) adjustment.” Several years of missed acceleration therefore land in a single return.
This is frequently a better result than the year-of-purchase case, because the catch-up is larger. It is also the version most owners do not know exists.
What happens when you sell
Everything above is timing — and the bill arrives on sale. The components reclassified as personal property are section 1245 property, and gain up to the depreciation allowed or allowable is recaptured as ordinary income at your regular rate. The building portion is section 1250 property, and the depreciation taken on it comes back as unrecaptured section 1250 gain, taxed at a maximum of 25%. Neither receives long-term capital gain treatment.
That does not make a study a bad idea. Deferring tax for years is worth real money, and a 1031 exchange can defer the recapture again. But a large first-year deduction is a loan against a future tax bill rather than a gift — and anyone selling it to you without saying so is not describing the whole transaction. Our guide to depreciation recapture works through the arithmetic on a sale.
What to do about it
The order matters more than the decision.
- Run the passive analysis first. Before commissioning anything, establish whether the loss will be usable in the year you want it. That answer, not the size of the deduction, decides whether a study is worth buying.
- Decide before you close, where you can. The purchase price, the closing date and how you intend to operate the property all change the result, and all of them are easier to influence before the transaction than after it.
- Match the study to the property. Engineered where the basis and complexity justify it, virtual where they do not.
- Place the property in service in the year you want the deduction. Ready and available for rent is the test — not occupied. A late-December closing is tight.
- Keep the participation log from month one if you are relying on the short-term rental route or on real estate professional status. A log kept during the year survives examination; one reconstructed afterward does not.
Frequently asked questions
Is a cost segregation study worth it on a rental property?
On the arithmetic alone, usually yes above roughly $300,000 of building basis: a study costing $1,000 to $4,000 commonly accelerates six figures of depreciation into year one. Whether it is worth it for you depends on whether you can use the loss. If your rental losses are passive and you have no passive income, the deduction is suspended and the study buys a slower benefit than the headline suggests. Settle that question before commissioning anything.
How much does a cost segregation study cost?
An engineered study with a site inspection generally runs $3,000 to $4,000. A virtual study without a site visit, appropriate for smaller residential properties, is usually $1,000 or less. Those fees go to the specialist firm performing the study. Applying it on your return is separate work, and we charge $1,500 to $2,000 for a standard rental on Schedule E with an otherwise straightforward personal return.
Can I do a study on a property I have owned for several years?
Yes, and it is often the better case. You file Form 3115 to change your method of accounting for depreciation, and a section 481(a) adjustment captures everything you should have deducted in prior years. A favorable adjustment is taken entirely in the year of change, so several years of missed acceleration land on one return. No prior returns are amended.
Does a cost segregation study increase audit risk?
A properly conducted study does not, and the IRS publishes the standard it expects in its Cost Segregation Audit Techniques Guide. What draws attention is an aggressive reallocation percentage unsupported by an engineering analysis, or a study used to claim losses the passive activity rules do not allow. The study is rarely the weak point. The participation claim usually is.
Is cost segregation only for commercial properties?
No. Residential rental property depreciates over 27.5 years against 39 for nonresidential, so the gap between the default schedule and the reclassified components is wider on residential. Single-family rentals and small multifamily buildings are routine candidates. What changes on a smaller property is which kind of study is economic, not whether the tax treatment applies.
What happens to the deduction when I sell?
It comes back. Components reclassified as personal property are section 1245 property and recapture as ordinary income at your regular rate. The building portion returns as unrecaptured section 1250 gain, taxed at a maximum of 25%. Neither gets long-term capital gain treatment. A 1031 exchange can defer it again, but the benefit is timing rather than permanent savings, and it should be evaluated that way.
Should I take 100% bonus depreciation or elect a lower percentage?
Take the full amount when you can use it. Notice 2026-11 allows an election to deduct 40% instead of 100% for property placed in service in the first tax year ending after January 19, 2025, and that election is worth considering when a full deduction would be wasted: suspended by the passive rules, stranded above the section 461(l) threshold, or larger than the income available to absorb it. Electing down spreads the deduction into years where it does something.
How long does a study take?
A virtual study is typically two to three weeks. An engineered study with a site inspection usually runs three to six weeks depending on the firm’s schedule and how quickly the closing documents, the appraisal and the property records are available. Commission it well before the return deadline rather than in the week before filing.
Related reading
- Cost segregation for Airbnb. The same analysis where the passive problem largely disappears.
- Cost segregation vs bonus depreciation. Why they are not alternatives.
- Cost segregation on ground-up construction. How new builds differ from acquisitions.
- How to calculate depreciation. Recovery periods, methods and conventions.
- Depreciation recapture on a sale. What the deferral costs at the end.
- Real estate professional status. The 750-hour rule, written out.
- Material participation for short-term rentals. The 100-hour test.
- The excess business loss limit. The ceiling above the passive rules.
- When depreciation stops. The end of the schedule.
- Real estate tax services. What we do and what it costs.
Schedule a call
A short conversation about your situation, our read on it, and whether it is a mutual fit. We can run a preliminary estimate of what a study would return on your property, and tell you whether the loss would be usable, before you commission anything.
General information, not advice for your situation. Figures apply to the 2026 tax year and are illustrative. Sources: IRS Publication 946, Notice 2026-11, IRS Publication 5653, Rev. Proc. 2025-32, Instructions for Form 3115, IRC section 469, section 1245 and section 1250.
