Cost Segregation Under $500K: When the Study Pays for Itself

A cost segregation study on a $380,000 rental can produce a first-year deduction above $84,000 where the ordinary schedule gives about $11,000. At an example 24% bracket that is $17,577 of tax saved in year one, from a study that costs a few thousand dollars.

Reviewed against IRS Publication 946 on depreciation and IRS Publication 544 on asset dispositions and IRS audit technique guides on October 1, 2026. Use the instructions for your filing year; the examples are planning illustrations, not a prepared tax return.

A study moves deductions forward in time and creates none. You give up smaller deductions in later years and you face a larger recapture bill at sale. Run through a ten-year hold with conservative assumptions, that $17,577 is worth about $5,844 in present value, and only if you can use the deduction in year one. Many owners of small rentals cannot. This post is about whether a cost segregation study on a small rental is worth it, and the answer depends on three inputs: your bracket, your hold period, and whether the passive loss rules let the deduction through.

The small-property question: study cost vs deduction value

On a $5 million apartment building, the study fee is a rounding error against the benefit. Under $500,000, the fee is a real share of the prize, so the math has to be done per property.

The mechanism is covered in our cost segregation guide for rental property, so here is only the one-paragraph version. A study reclassifies part of the building's cost from 27.5 year property into 5, 7 and 15 year property. Under 100% bonus depreciation, those shorter-lived pieces are deducted entirely in the first year. The land and the remaining structure are unaffected.

What you are buying is an interest-free loan from the Treasury. You receive tax savings now and repay them through lower depreciation each year after, and through recapture when you sell. The value of the study is the time value of that loan, adjusted for any difference between the rate you deduct at and the rate you repay at. The fee is what you pay to arrange it.

That framing produces four questions: how big the loan is, how long you keep it, what rate you repay at, and whether the passive loss rules let you receive the money at all this year.

What a study finds in a typical single family

As a rule of thumb, a study on a single family or small residential rental moves 20% to 30% of the building's depreciable basis into shorter lives. Newer homes with more site work land higher and plain older houses on small lots land lower. Treat the range as a planning assumption, not a promise from any provider.

What gets reclassified:

• 5 year property: appliances, carpet and other removable floor coverings, window treatments, some cabinetry and millwork, and wiring or plumbing that serves specific equipment.
• 15 year property: land improvements such as driveways, walkways, fencing, landscaping, patios and exterior lighting.
• Stays at 27.5 years: the structure itself. Framing, roof, walls, windows, general plumbing and electrical, HVAC.

Here is the example property used for the rest of this post, with invented figures and depreciation simplified to full years.

Without a study, annual depreciation is $304,000 divided by 27.5, or $11,055.

With a study and 100% bonus, year one is $76,000 plus $228,000 divided by 27.5, which is $76,000 plus $8,291, or $84,291. Every year after that is $8,291.

So the study adds $73,236 of deductions in year one ($84,291 less $11,055) and removes $2,764 from every later year ($11,055 less $8,291).

Whether you get 100% depends on the acquisition and placed-in-service facts. The July 2025 tax law made 100% bonus permanent for qualified property acquired after January 19, 2025, subject to the acquisition, binding-contract and placed-in-service rules. Property acquired on or before that date gets 40% if placed in service in 2025 and 20% in 2026. The bonus depreciation calculator sorts out which percentage applies, and the background is in our post on bonus depreciation in 2026. A different bonus percentage needs a new annual depreciation and exit model; do not reuse the figures below.

Study options by price: full engineering to DIY software

Providers sort into three tiers. The prices below are example figures used for the math in this post, not quotes and not a market survey. Get at least three quotes for your own property.

The IRS publishes an audit techniques guide for cost segregation that describes what a quality study contains: a clear methodology, reconciliation of the allocated costs to your actual total cost, and documentation behind each reclassified component. The further a report is from that description, the more of the risk sits with you. Ask any provider for a sample report, and ask your tax preparer whether they will file on it.

Against the example benefit computed in the next section ($5,844 in present value at a 24% bracket), the tiers net out like this:

On a small house, a full site-visit study can cost more than the timing benefit is worth. The fee is generally deductible, which the tables here ignore to stay conservative.

The break-even math: tax bracket decides

Here is the full worked example at a 24% federal bracket. The assumptions: the owner can use the entire deduction in year one, holds for ten years, then sells in a taxable sale. Money is discounted at an example 6% a year. For this conservative sensitivity only, the entire $76,000 accelerated amount is assumed taxable at the ordinary rate at sale. Actual Section 1245 and Section 1250 classification, sale allocation and recognized gain must be determined asset by asset. The unreclassified structure's depreciation uses the assumed rate capped at 25%. Calculations retain unrounded inputs until display.

Step 1: year one. Extra deduction of $73,236 at 24% saves $17,577.

Step 2: years 2 through 10. The owner gives up $76,000 / 27.5 of depreciation annually. At 24%, nine years cost $5,969 in total, rounded after calculation.

Step 3: the sale in year 10. The assumed tax on $76,000 at 24% is $18,240. Without the study, ten full years of depreciation on that slice total $27,636.36, producing $6,632.73 at 24%. The difference is $11,607.27, displayed as $11,607.

Step 4: add it up without discounting. Using unrounded figures, $17,576.73 less $5,969.45 less $11,607.27 is zero apart from displayed cents. In this constant-rate sensitivity at 24%, the value comes from timing.

Step 5: discount it.

A $3,500 study returns $2,344 of present value after its own cost, nowhere near the $17,577 headline.

The same model at other brackets, all else equal:

At 12%, the study loses money even when the deduction is fully usable. The benefit flattens above 25%, because a high-bracket owner repays the reclassified piece at 32% or 37% under the conservative assumption, not at the 25% cap that applies to the structure. The present value of the benefit is also the most you should pay for the study. At 24% in this example, that ceiling is $5,844.

The recapture at sale can be smaller than modeled here. Ten-year-old carpet and appliances are worth far less than they cost, and a sale allocation that reflects that reduces the ordinary-rate piece. Raise that with the CPA who prepares the sale. A different defensible asset allocation changes the exit calculation; do not assume a particular reduction without the facts.

When it backfires: low brackets, short holds, passive limits

The table above assumes the deduction is usable in year one. For many small landlords it is not.

Rental losses are passive by default. The $25,000 special allowance phases out between $100,000 and $150,000 of modified AGI. So the owners in the 24% bracket and above, who benefit most on paper, are often the same owners whose income blocks the loss. A suspended loss carries forward and releases when passive income appears or on a qualifying fully taxable disposition of the entire activity interest to an unrelated buyer. A deduction you cannot use yet has time value, not face value. If it waits until the sale, it arrives in the same year as the recapture it was supposed to beat.

Here are selected sensitivities using the same unrounded model. The fully suspended cases assume no relevant deduction benefit is available until the taxable sale. They do not model a separate return with other passive income or a partial special allowance.

Short holds. In the displayed three-year cases the timing benefit does not recover the assumed fee. That is a result of these inputs, not a universal rule for all studies.

The $25,000 allowance. An eligible actively participating owner may have a special allowance of up to $25,000 against non-passive income, subject to filing-status and other limits. For a separate illustrative allowance case, assume $7,000 of annual income before depreciation and eligibility for the full allowance each year. The first-year loss is about $77,291. Later losses and the carryforward must share the annual allowance. Prepare an annual return projection; the fully usable and fully suspended rows above do not price this partial-use case.

Fully suspended. An owner above $150,000 with no passive income gets nothing until sale. At 24% the study is a pure loss of the fee. At 32% it is slightly worse, because without a study that slow depreciation would have been released at 32% and recaptured at only 25%. The study gives up that 7 point spread on $27,636.36, which is about $1,935 in year 10, or $1,080 today.

Who can use it in year one. Households where one spouse qualifies as a real estate professional and the rental activity meets material participation requirements. Short-term rental owners whose average stay is 7 days or less and who meet a material participation test, which needs a CPA's review. Owners with passive income from other rentals or partnerships that the loss can absorb. Owners eligible for a partial special allowance need a separate annual projection rather than either extreme row.

Two more ways it disappoints:

• State taxes. Many states do not follow federal bonus depreciation, so the state side of the benefit may be small or zero.
• Excess losses. A very large deduction can spill into lower brackets than the one used in the estimate.

An exchange or inheritance changes the exit model. Section 1031 applies to qualifying real property, so a cost-segregation schedule can contain assets whose sale treatment differs from the building's. Do not assume every accelerated deduction avoids recapture indefinitely.

Run your property's numbers

The decision comes down to five inputs you already know or can estimate:

1. Depreciable building basis, after removing land.
2. Acquisition and placed-in-service dates, including applicable transition rules.
3. Your federal bracket, and whether your state follows bonus depreciation.
4. Whether the loss is usable: your modified AGI against the $100,000 to $150,000 range, any passive income, and whether real estate professional status or the short-term rental rules apply.
5. Expected hold period and exit (taxable sale, exchange, or hold indefinitely).

In this example, the 12% and short-hold cases do not recover the fee. A different reclassified share, fee or exit allocation could change that result. If your income blocks the loss and there is no usable passive income or exception, model the delay explicitly before buying a study. You can generally have a study done in a later year and catch up the missed depreciation through an accounting method change without amending past returns, subject to method-change eligibility, filing costs and the time value of delayed deductions. The applicable bonus percentage still depends on the original acquisition and placed-in-service facts.

If you pass the screen, the cost segregation calculator provides a planning estimate. Reconcile its assumptions to the study proposal and a separate tax projection; it is not a component study or this exact multi-year tax model. Enter your property's figures and compare the result to the quotes you receive. Buy the study only when the present value of the benefit clears the fee with room to spare, and only after your CPA confirms the deduction will reach your return this year.

This article is general information, not tax advice. Rules change and individual situations differ: confirm anything you plan to act on with a CPA.

Keep a separate operating case in the single-family calculator, using actual financing and cash expenses before adding any assumed tax benefit.