Cost Segregation Study Costs, Process, and 2026 Rules
A cost segregation study separates qualifying building components into shorter depreciation periods. This guide explains how the study works, what it costs, and how to evaluate the potential benefit for your property.
35 min read Updated September 23, 2026 Written by Taxstra PLLC
Written by Bryan Martin, CPA, Managing Partner and Founder of Taxstra. Last updated September 23, 2026.
Tax rules updated September 23, 2026. Study-classification guidance checked against IRS Publication 5653.
Quick answer
A cost segregation study documents which property costs belong to shorter-life assets rather than the building structure. Eligible property acquired after January 19, 2025 may qualify for 100% bonus depreciation, but the study itself does not establish eligibility or whether you can use a resulting loss. Compare the provider’s documented estimate and fee with your acquisition records, passive-activity position, and expected sale before commissioning a study.
Section 01
What Is Cost Segregation?
Understand the study before deciding whether to commission one.
A cost segregation study is an engineering-based tax strategy that identifies components of a building that can be depreciated over shorter time periods than the standard 27.5 years (residential) or 39 years (commercial). Instead of treating your entire building as a single asset that slowly depreciates over decades, a study breaks the property into its individual components, and reclassifies those that qualify into 5-year, 7-year, or 15-year asset classes.
The purpose is to move qualifying depreciation deductions into earlier years. Whether that helps you now depends on your property and your tax situation, so the projected deduction needs to be reviewed alongside the study fee and your ability to use the loss. The worked examples below show how to approach that comparison.
The IRS Cost Segregation Audit Techniques Guide describes the issues examiners consider when reviewing a study. Its discussion of asset classification and supporting records is useful when comparing providers: ask how the report will support the costs and recovery periods assigned to your property.
How 100% Bonus Depreciation Affects the Study
Under the Tax Cuts and Jobs Act (TCJA) of 2017, 100% bonus depreciation was available for assets placed in service through 2022. After that, it began phasing down: 80% in 2023, 60% in 2024, and was scheduled to drop to 40% in 2025, 20% in 2026, and 0% in 2027.
The One Big Beautiful Bill Act (OBBBA), signed on July 4, 2025, changed the bonus depreciation rules. The law permanently restored 100% bonus depreciation for qualifying property acquired after January 19, 2025, with no scheduled phase-down. (Property acquired on or before January 19, 2025 stays on the old phase-down percentages even if placed in service later.) This means every dollar reclassified by a cost segregation study into a shorter-life asset class can potentially be written off entirely in Year 1.
That makes the acquisition and placed-in-service dates important parts of the initial review. Give the study provider and your CPA the same purchase and project records so their projections start from the same facts.
Key Facts at a Glance
What It Is
Engineering-based study that reclassifies building components for faster depreciation
Tax Code
Section 168 (MACRS) and Section 168(k) (Bonus Depreciation)
Possible Result
Supported assets may move to 5, 7, or 15-year recovery periods
Year 1 Impact
Can generate 5-10x the normal first-year depreciation deduction
Study Cost
$2,000 to $15,000 (engineer-reviewed residential to full commercial engineering study)
Property Minimum
No universal threshold; compare fee, basis, records, and usable deductions
Bonus Depreciation
100%, permanently restored by the OBBBA (July 2025) for property acquired after Jan 19, 2025
Look-Back Available
Yes, catch up missed depreciation from prior years via Form 3115
Start with the feasibility review. A useful estimate explains what the provider expects to reclassify, what the study will cost, and which assumptions your CPA needs to check before you rely on the projected benefit.
Section 02
How a Cost Segregation Study Works
The step-by-step process from initial analysis to claiming your deductions.
The study turns a broad property cost into a supported asset schedule. To do that, the provider needs to understand what was purchased or built, how the components function, and which records support their cost. Purchase documents, construction invoices, plans, and information about improvements all help establish that picture.
Classification comes next. A component’s name alone does not settle its treatment; the report needs to explain the distinction between personal property, land improvements, and structural components. Those conclusions are what your CPA uses when putting the study into the depreciation schedule.
The Study Process
1
Feasibility Analysis. Ask the provider to review your property type, depreciable basis, available records, placed-in-service date, proposed scope, and fee before commissioning a study.
2
Site Visit & Engineering Analysis. Licensed engineers physically inspect the property, review construction blueprints and invoices, and identify every component that can be reclassified. This is the core of an engineering-based study.
3
Cost Allocation. The engineering team assigns a dollar value to each identified component using one or more accepted methodologies: detailed engineering approach (preferred), residual estimation, or sampling/modeling.
4
Report Preparation. A detailed report is prepared documenting every reclassified asset, its cost, depreciation class, and the methodology used. A quality report follows the IRS Audit Techniques Guide framework.
5
Tax Return Integration. Your CPA reviews the report, asset eligibility, elections, and loss limitations and incorporates supported amounts into the return. A look-back may require Form 3115 or another filing method.
6
Ongoing Depreciation Schedule. The study creates a new depreciation schedule that replaces the old single-asset approach. Your CPA uses this schedule for all future returns.
Timeline
Ask the provider for a delivery date before engaging. Inspection, records, engineering work, and tax-return coordination can change the timeline. Agree with your CPA on when the final report is needed for the filing position being considered.
Accepted Study Methodologies
The IRS recognizes several approaches to performing a cost segregation study. The quality and defensibility of the study depends heavily on which methodology is used:
Detailed Engineering Approach (Preferred)
A detailed engineering method uses property records, inspection findings, and documented cost estimates to support component-level allocations. Ask what the provider will inspect and how the report will explain disputed classifications.
Residual Estimation Approach
Costs are determined by subtracting the known cost of structural components from the total building cost. The remainder is allocated among shorter-life assets. Less precise than the engineering approach but acceptable when construction records are limited.
Sampling / Modeling Approach
Used for portfolios of similar properties (e.g., a chain of retail locations). A detailed study is performed on a representative property, then results are extrapolated to similar properties with adjustments. Cost-effective for large portfolios.
Avoid 'Rule of Thumb' Studies
Some providers use broad percentages with little property-specific support. Ask how the report ties asset classifications and allocated costs to plans, invoices, inspections, or a documented estimating method.
Section 03
How Much Does a Cost Segregation Study Cost?
What to expect to pay, what drives the price, and how to know if the math works for your property.
Market pricing varies by property, methodology, inspection scope, and post-delivery support. The ranges below were checked on August 10, 2026 against current published-market datasets and provider pricing. They are planning ranges, not Taxstra quotes.
Study type
Observed 2026 range
Typical fit
Residential rental, engineer-reviewed study
$2,000 to $4,500
Single-family, duplex, or small multifamily
Commercial property under roughly $2 million
$4,000 to $7,000
Smaller office, retail, industrial, or mixed-use property
Larger or complex commercial property
$10,000 to $15,000+
Large basis, specialty systems, portfolio, or reconstruction-heavy work
Market references: 60-provider pricing dataset and 27-provider pricing review, both current through May 2026. Taxstra has not independently audited every underlying quote. Confirm scope and price in the engagement letter.
What drives the fee
Two properties with the same purchase price can require very different amounts of work. The condition of the records, the complexity of the building, and the inspection and reporting scope all affect the quote. Ask providers to explain these differences when comparing fees:
Building size and basis. More square footage, more units, and more site work mean more components to identify and price.
Methodology and site visit. A detailed engineering study with a physical inspection costs more than a virtual or software-assisted report; the IRS Cost Segregation Audit Techniques Guide describes the detailed engineering approach as the most accurate and best documented.
Property complexity. Specialty systems (commercial kitchens, medical gas, process electrical, pools, fuel systems) take longer to segregate than a plain residential rental.
Quality of records. Closing statements, construction draws, and blueprints shorten the work; reconstructing costs from scratch adds hours.
Look-back scope. Reviewing prior-year schedules and the appropriate filing method adds CPA coordination, which some providers price separately.
Audit support. Whether the provider defends the study if it is examined, and for how many years, is part of what you are paying for.
Flat fee vs. percentage-of-benefit pricing
A flat fee makes the provider's incentive and your break-even math easier to see. A benefit-based fee can scale with the projected result, but the contract should define the assumed tax rate, bonus-depreciation treatment, loss usability, and what happens when your CPA changes the provider's estimate. Compare the deliverable, not just the headline fee.
For a quick first pass at these numbers, SMF Cost Seg offers a free Cost Seg Estimate Calculator that models the projected benefit for your property before you spend anything on a study.
The word usable matters. Passive-activity limits, at-risk limits, business-use rules, state conformity, future recapture, and the timing of your eventual sale can reduce or defer the benefit. A large depreciation number is not the same as an immediately usable tax deduction.
Because the study has a real cost, there is a break-even point. As a rule of thumb, a study is worth exploring when:
The modeled benefit clears the fee by a comfortable margin, even after conservative assumptions and added return-preparation cost.
The study matches the property's complexity, instead of paying for an enterprise engagement on a simple rental or using a rules-of-thumb report on a complex building.
Your tax preparer reviews the feasibility estimate, including basis, placed-in-service date, loss limitations, state treatment, and exit horizon.
When a study may not be worth it
Smaller properties can work, but there is no universal minimum basis. Be skeptical when the projected usable tax benefit barely exceeds the fee, the property may be sold soon, records are weak, or losses are likely to remain suspended. The plan's suggested $150,000 to $300,000 cutoff is a screening range, not a tax-law threshold.
The federal tax treatment of the study fee depends on the facts and how the work is used; do not assume every fee is immediately deductible. Taxstra can review the provider scope and return implementation within a paid engagement.
Choose the study before the provider
Start with the property and the tax-return question. Then compare provider models, inspection methods, deliverables, and support in our cost segregation company selection guide.
Section 04
Cost Segregation Visual Component Atlas
See both sides of the classification boundary before treating a component as shorter-life property.
MACRS assigns depreciable property to recovery periods. Cost segregation does not simply move anything removable into a shorter life: function, attachment, the business activity, and what the system serves determine whether a component is a classification candidate or stays with the building.
See the classification boundary, component by component
Search 28 common building and site components. Each diagram shows the shorter-life fact pattern beside the condition that can keep the same-looking item with the building or land.
Screening guide only. Function, attachment, business activity, and engineering records control. The IRS audit guide supplies practical examination examples but says it is not legal authority.
Find a component
Showing 28 of 28 components
Interior finishes5-year
Readily removable floor coverings
Attachment and intended permanence separate the shorter-life candidate from the structural floor.
Shorter-life candidate
5-year
Section 1245
The covering can be readily removed without material damage or can be moved and reused, stored, or sold. The residential matrix treats VCT, sheet vinyl, and carpeting as nonpermanent.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
The IRS residential matrix distinguishes a circuit dedicated to an appliance from outlets of general applicability.
Shorter-life candidate
5-year
Section 1245, Asset Class 57.0
The outlet, wire, conduit, and breaker are necessary to and used directly with a specific appliance, such as a dryer, range, washer, dishwasher, refrigerator, or built-in microwave.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
Equipment-serving share of electrical distribution
Shared electrical cost is not classified by a blanket percentage; the IRS guide describes allocation by end-use design load.
Allocated shorter-life candidate
5-year or applicable equipment life
Section 1245 share
Engineering support allocates the primary and secondary distribution cost to qualifying equipment loads using design-load or another reasonable functional method.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
Accent-only, building-mounted, and freestanding site lights can land in three different treatments.
Accent-light candidate
5-year in the cited residential context
Section 1245
The light highlights only landscaping or the building exterior and does not illuminate parking, walkways, or entrances or otherwise serve building operation.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
This is highly context-specific: a retail display can be shorter-life while residential kitchen cabinetry is not.
Retail or restaurant candidate
5-year
Section 1245, Asset Class 57.0
Decorative finish carpentry, cabinets, cashwraps, counters, or toppers enhance the selling or dining theme and do not operate or maintain the building.
The work is kitchen or restroom cabinetry, finish carpentry, doors, frames, trim, stairs, panel work, or other general building millwork. The residential matrix places kitchen and restroom cabinetry at 27.5 years.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
Constructed circulation surfaces are distinct from the underlying land and general grading.
Land-improvement candidate
15-year
Asset Class 00.3, Sections 1245/1250
Grade-level roads, driveways, base areas, guardrails, curb cuts, curbs, and sidewalks are constructed of asphalt, concrete, brick, stone, or similar materials.
The cost is initial clearing, stripping, mucking, or general grading that prepares the site rather than finish grading tied to the constructed improvement.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
These constructed site features commonly sit in Asset Class 00.3 when they are depreciable and not part of a building.
Land-improvement candidate
15-year
Asset Class 00.3, Sections 1245/1250
The improvement is directly to or added to land, such as a fence, gate, retaining wall, fountain, drainage facility, detention pond, or irrigation system.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
Mounting and served area separate a site-light system from lighting attached to and operating the building.
Land-improvement candidate
15-year
Asset Class 00.3, Sections 1245/1250
A pole-mounted or freestanding system illuminates sidewalks, parking, or recreation areas and includes its site foundation and associated site components.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
Physical separation from the building is a central boundary for these outdoor amenities.
Land-improvement candidate
15-year
Asset Class 00.3, Sections 1245/1250
An inherently permanent deck or gazebo is not attached to a building, or a ground-level paved patio adjoins the property as a constructed land improvement.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
Locks, cameras, motion detection, lighting, alarms, wiring, and conduit protect the building, its contents, and occupants as a building security system.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
Grading and footings for specific site improvements
Below-grade cost follows what it directly supports; general site preparation remains a land cost.
Land-improvement candidate
15-year
Asset Class 00.3, Sections 1245/1250
Excavation, backfill, reinforcement, concrete, base course, or fine grading directly constructs a sign, light pole, parking lot, road, sidewalk, or another depreciable site improvement.
Initial clearing, stripping, mucking, or general site grading prepares the land and would not need to be repeated when a particular depreciable improvement is replaced.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
IRS Publication 5653 is examination guidance, not an official IRS pronouncement or a substitute for the Code, regulations, and applicable revenue procedures.
The atlas helps you ask better questions. An engineer still has to measure the component, trace the systems, allocate indirect costs, and tie the result to your basis. Your CPA then determines whether the deduction is usable and implements it on the return.
Consider a $100,000 component in a commercial building. Under the default 39-year classification, you'd deduct approximately $2,564 per year. But if that same component qualifies as 5-year personal property:
As a simple illustration, a supported $100,000 component classified as five-year property follows a different deduction schedule from a component that remains part of a 39-year building. The first-year amount depends on the depreciation convention, bonus eligibility, elections, and placed-in-service date. A study must support the classification before your CPA can calculate the schedule.
Qualified Improvement Property (QIP)
Certain interior improvements to a nonresidential building may qualify as 15-year QIP when the statutory conditions are met. Enlargements, elevators and escalators, and internal structural framework are excluded. Review the work and dates before assuming bonus eligibility.
Section 05
Cost Segregation + Bonus Depreciation
Which assets and dates can change the first-year deduction.
The Bonus Depreciation Timeline
Bonus depreciation (Section 168(k)) allows businesses to immediately deduct a percentage of the cost of eligible assets, rather than depreciating them over their full recovery period. (For the complete rules, qualifying assets, vehicles, Section 179 interaction, and recapture, see our full bonus depreciation guide.) Here's how the rules have evolved:
Period
Bonus %
Authority
Sept 2017 to Dec 2022
100%
TCJA
Jan 2023 to Dec 2023
80%
TCJA phase-down
Jan 2024 to Jan 19, 2025
60%
TCJA phase-down
Acquired and placed in service after Jan 19, 2025
100%
OBBBA (permanent)
What Qualifies for Bonus Depreciation
Bonus depreciation applies to property with a MACRS recovery period of 20 years or less. In the context of cost segregation, this means:
5-year property, personal property, carpeting, appliances, certain fixtures
7-year property, certain activity-specific equipment and assets classified under the applicable revenue procedure
15-year property, land improvements (parking lots, landscaping, fencing, sidewalks)
Qualified Improvement Property (QIP), interior improvements to nonresidential buildings (15-year)
27.5-year and 39-year property, structural building components do NOT qualify for bonus depreciation
Check the Asset and the Date
A study can identify shorter-life assets within a property. Some may qualify for bonus depreciation, while the building structure generally does not. Ask the provider and CPA to document classification, acquisition date, placed-in-service date, and elections for each asset class.
Electing Out of Bonus Depreciation
You can elect out of bonus depreciation by class of property under the applicable rules. Model current and future taxable income, loss limitations, state treatment, and a potential sale before deciding. The largest first-year deduction is not always the best overall tax result.
Section 06
Cost Segregation by Property Type
The records and components to review by building type, plus dedicated guides.
Reclassification depends on the property's actual components, costs, and supporting records. These prompts identify what to ask the study provider to examine; they are not projected deduction percentages.
🏢
Apartment Complex
Study result
Varies by components
Review item
Ask for an asset schedule
🏠
Single-Family Rental
Study result
Varies by components
Review item
Separate land and building
🏗️
Office Building
Study result
Varies by components
Review item
Review tenant improvements
🏪
Retail / Restaurant
Study result
Varies by components
Review item
Review site improvements
🏭
Industrial / Warehouse
Study result
Varies by components
Review item
Review specialty systems
🏥
Medical / Dental Office
Study result
Varies by components
Review item
Review specialty equipment
🏨
Hotel / Hospitality
Study result
Varies by components
Review item
Review furnishings and site
📦
Self-Storage Facility
Study result
Varies by components
Review item
Review paving and systems
Restaurants and Retail: Review the Asset Mix
Restaurants and retail properties can have substantial equipment-serving systems, kitchen or refrigeration equipment, displays, decorative finishes, and site improvements. That makes them strong feasibility candidates, but basis, study cost, classification support, loss usability, state treatment, and exit timing still determine whether the study is worthwhile.
Dedicated guides by building type
Each guide below explains components worth reviewing for that building type. The allocation and any tax benefit depend on the actual property and owner. Browse the cost segregation by property type hub, or go straight to your building:
A short-term rental with an average customer use of seven days or less may fall outside the rental-activity definition for passive-loss purposes. Material participation and other limitations still determine whether a resulting loss is usable against wages. See the short-term rental guide for the tests and records involved.
Section 07
Cost Segregation Study Examples
Illustrative questions to work through before relying on a provider's projection.
1
Apartment purchase
An owner buys an apartment building for $2 million, including land.
First separate land from depreciable basis. Ask the provider which costs it can support as shorter-life assets and what records establish those costs. Then have your CPA test the acquisition date, bonus eligibility, passive-loss limits, and likely sale treatment. A percentage of purchase price alone cannot answer those questions.
2
Owner-occupied office
A practice buys a medical office with equipment and interior improvements.
Keep separately purchased equipment and qualified interior improvements distinct from the building purchase. The study should identify each asset, its cost basis, and why its recovery period applies. Compare the incremental deductions with the study fee and the practice's projected taxable income.
3
Short-term rental
An employee buys a cabin and plans to rent it for short stays.
A study may identify shorter-life assets, but using any resulting loss against wages is a separate question. The average customer use, services provided, material participation, at-risk amount, and other tax facts need review before projecting a current benefit.
4
Property already in service
An owner has depreciated a retail property for several years without a study.
A later study can identify potential classification changes. The acquisition-year rules and prior depreciation schedule control the calculation. Ask your CPA whether a change in accounting method and Form 3115 apply; do not treat a current-year catch-up amount as automatic.
Section 08
The Look-Back Study
How to review property already in service.
What Is a Look-Back Study?
A look-back study examines property placed in service in a prior year. It identifies supported asset classifications and compares them with the depreciation already claimed. Your CPA must determine the correct filing method and any adjustment under the rules for that acquisition year.
In some cases, a change in accounting method uses Form 3115 and a Section 481(a) adjustment. It is not automatic for every property or every error. Have your CPA review prior returns, placed-in-service dates, and current IRS procedural guidance before choosing Form 3115 or amended returns.
How the Catch-Up Works
1
Perform the study. The engineering analysis is identical to a study on new property. The firm identifies and classifies all shorter-life components.
2
Calculate "should have been" depreciation. The firm calculates what your total depreciation deductions would have been from the placed-in-service date through the current year if the study had been done originally.
3
Compare to actual depreciation. Your CPA compares the supported schedule with prior returns and determines whether an accounting-method adjustment is permitted.
4
Choose the filing method. Your CPA determines whether Form 3115, an amended return, or another treatment applies and calculates any permitted adjustment.
Review Prior Returns First
A later study may produce a catch-up adjustment when the accounting-method rules permit it. The amount and filing route depend on the existing depreciation schedule and the year the property entered service.
When a Look-Back Study Makes Sense
You purchased or built a property in any prior year and never did a cost segregation study
You have a high-income year and need additional deductions to offset income
Your participation or other income changed, so your CPA should reassess whether a resulting loss could be used
Your short-term rental records may support a different passive-activity analysis
The property still has significant remaining depreciable basis (i.e., you haven't fully depreciated it yet)
Important Limitation
A look-back calculation uses the rules applicable when each asset was acquired and placed in service, including the bonus depreciation rules for that year. A later study does not reset the asset's acquisition date or guarantee a 100% catch-up deduction.
Section 09
Who Should Consider a Study
Cost segregation isn't for every property, but it's for more properties than most people think.
Ideal Candidates
Meaningful depreciable basis. Compare the proposed fee with the supported allocation and your ability to use the deduction; there is no universal dollar cutoff.
New construction. Building records can provide stronger cost support; bonus eligibility must still be checked asset by asset.
Recent purchases. Properties acquired in the last 1-3 years are prime look-back candidates
Major renovations. Significant build-outs and improvements can be studied independently
High-income owners. The higher your tax bracket, the greater the dollar value of accelerated deductions
REPS or STR owners. Those who can use depreciation losses against active/W-2 income see the biggest impact
When It May Not Be Worth It
Very low building basis. Properties under $200K building value may not generate enough benefit to justify study costs
Planning to sell within 1-2 years. Depreciation recapture upon sale may offset much of the near-term benefit
Low tax bracket with no passive income offset. If you're in a low bracket and can't use passive losses, the deductions may have limited value
Raw land. Land is not depreciable and cost segregation only applies to building components and improvements
Is a Cost Segregation Study Worth It? Use the Flowchart
Walk through the questions that affect a study's potential value: depreciable basis, holding period, how the property is used, and whether you can use the deductions. The flowchart highlights what to investigate; it does not calculate eligibility, tax savings, or a return on investment.
COST SEGREGATION DECISION PATH
Choose the closest answers to see which questions deserve a closer look. The path is educational and cannot decide whether a study is worthwhile for your return.
Depreciable building basis
About how much basis is allocated to the building, excluding land?
Compare the depreciable basis, study scope and quoted fee before estimating any benefit. Purchase price alone cannot answer the question.
START
Educational information, not individualized tax advice. This tool does not estimate tax savings or determine eligibility. Professional analysis of your property and return requires a paid engagement.
Get a Scoped Proposal
Ask a provider for the proposed method, required records, fee, report deliverables, and support if the IRS asks questions. A preliminary estimate is a screening tool, not an eligibility decision or a promised tax benefit. Taxstra can coordinate a provider within a paid planning engagement.
Section 10
Can I Do My Own Cost Segregation Study?
DIY estimates, desktop studies, and full engineering studies, what's defensible and when.
Technically, nothing in the tax code requires you to hire anyone, the IRS accepts any cost segregation methodology that produces an accurate, well-documented allocation. Practically, the question is whether your numbers would survive an audit. The IRS Cost Segregation Audit Techniques Guide makes clear that quality is judged by the documentation and methodology behind the allocation, and a spreadsheet where you guessed "20% is probably personal property" has neither.
A desktop study may be appropriate when the property and available records support its method. Ask what component-level evidence it uses, what a site visit would add, and what support the provider offers if the IRS examines the allocation. Price alone does not establish the right scope.
For a complex property, compare the scope and documentation of an engineering study with a desktop method. The fee can be material, so evaluate it against projected usable deductions and exit effects. Our educational flowchart helps organize the questions before seeking a scoped proposal.
Where DIY Goes Wrong
A percentage without property-specific support can be challenged. Keep the records and calculations that connect each allocated cost to the asset and recovery period, whether you use a desktop method or an engineering firm.
Section 11
Depreciation Recapture
Model the sale as well as the current deduction.
Understanding Recapture Rules
Depreciation reduces adjusted basis. On a sale, the asset type and prior depreciation can change how much gain is taxed as ordinary income, unrecaptured Section 1250 gain, or another category. A future sale belongs in the study decision:
Include the Exit
Earlier depreciation can reduce current taxable income when the deductions are usable, and it can increase gain on a later sale by reducing adjusted basis. Model both sides using the expected holding period and asset classifications.
Asset Type
IRC Section
Recapture Rate
Personal Property (5/7-year)
Section 1245
Ordinary income rate (up to 37%)
Real Property (27.5/39-year)
Section 1250
25% (unrecaptured Sec. 1250 gain)
Land Improvements (15-year)
Classification varies
Confirm asset-level treatment
Questions for an Exit Model
A current deduction and a later tax cost occur at different times. Compare them using realistic assumptions:
Time Value of Money
When will the deductions be usable? How long is the property likely to be held? Model the present value of current and future tax effects without assuming a fixed investment return.
Rate Differential
Different assets can produce different gain character on sale. Do not assume all accelerated deductions reverse at one uniform rate; ask the CPA to model the actual asset schedule.
1031 Exchange Deferral
A qualifying like-kind exchange can defer some gain, but personal property and prior depreciation require separate review. See the guide on tax basis and model the proposed exchange before relying on deferral.
Compare the Full Timeline
A useful study comparison includes the fee, timing of usable deductions, tax effects on disposition, and any state differences. A first-year deduction by itself is not a return-on-investment calculation.
Section 12
Combining With Other Strategies
Loss limitations and other tax choices can change the result.
Can You Use the Deductions?
A study changes the timing of depreciation. Rental losses are generally passive, and at-risk and other limits can apply. These are two common situations to examine before assuming a loss can offset wages:
Real Estate Professional Status (REPS). REPS can change treatment of rental losses when the taxpayer also meets material-participation rules for the activity. See the cost seg + REPS guide.
Short-term rental activity. Average customer use of seven days or less can change rental-activity classification; material participation and other limits still matter. See the STR guide.
Without a current way to use a loss, depreciation may be suspended for future use. Review the activity, at-risk amount, and other passive income before paying for an acceleration that may have limited near-term value.
Real Estate Professional Status (REPS)
REPS status and material participation are separate tests. A taxpayer who meets both may treat the relevant rental activity as nonpassive, subject to other limits. See the REPS guide.
Short-Term Rental (STR) Loophole
Short average stays can put an activity outside the rental definition under the passive-activity rules. Material participation and the full tax picture determine whether a loss is usable. See the STR guide.
1031 Exchange + Cost Segregation
A replacement property can be reviewed, but exchange carryover basis, excess basis, and Section 1245 property require separate treatment. Coordinate any study with the exchange workpapers rather than assuming depreciation restarts.
QBI Deduction (Section 199A)
Depreciation can affect qualified business income when the rental activity is a trade or business. Model the QBI deduction together with the depreciation timing. See the QBI guide.
Entity Structure Optimization
Entity choice and partnership allocations affect how deductions reach owners. Allocation provisions must satisfy tax rules and should not be changed solely to route depreciation to one owner. Review the operating agreement and basis before making structural changes.
Partial Asset Disposition
A renovation may raise a partial-disposition question. The tax treatment depends on whether the old component's basis can be established and the applicable election and timing rules. Keep original cost and replacement records.
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Frequently Asked Questions
Engineer-based studies typically run $2,000 to $15,000 depending on property type and complexity: about $2,000 to $4,500 for engineer-reviewed residential studies, $4,000 to $7,000 for smaller commercial properties, and $10,000 to $15,000 or more for larger or complex commercial work. Scope and support matter more than the lowest quote.
No. A study can examine newly constructed, purchased, or renovated property. For property already in service, the filing method and any catch-up adjustment depend on the prior depreciation method and acquisition year; ask a CPA whether Form 3115 applies.
There is no universal tax-law minimum. Compare the provider's fee and documented reclassification estimate with your ability to use the deductions and your expected holding period. Exclude land from depreciable building basis.
It can be, but a smaller basis makes study fees more consequential. The decision also depends on the actual asset allocation, loss limitations, and how long you expect to own the property. The flowchart in the Who Should Consider a Study section walks through those questions.
It can. A study may identify shorter-life candidates such as removable floor coverings, appliances, furnishings, and qualifying site improvements. Installed cabinetry, finish carpentry, building-serving systems, land, and structural components require separate analysis and may remain 27.5-year property. Bonus eligibility and loss usability are separate questions.
Depreciation reduces adjusted basis and can affect the character and rate of gain on sale. Section 1245 and unrecaptured Section 1250 gain have different rules. Model the exit, holding period, and usable current deductions before deciding whether a study is worthwhile.
Yes. It restored a permanent 100% additional first-year deduction for eligible property acquired after January 19, 2025. An asset's acquisition and placed-in-service dates, eligibility, and elections still need review; the study alone does not establish the deduction.
A replacement property may be studied, but carryover and excess basis can have different depreciation treatment. Coordinate the exchange records, allocation, and depreciation schedules with your CPA and study provider.
Section 179 is an expensing election subject to annual limits and other requirements. A cost segregation study identifies the appropriate recovery period for supported property components; some assets may separately qualify for bonus depreciation. The study does not itself make an asset eligible for either deduction.
No. A study changes the depreciation schedule, but passive-activity rules determine whether a resulting loss is usable currently. REPS alone is not enough; material participation and other requirements matter. A qualifying short-term rental activity has separate rules.
A qualified study should be performed by a team that includes a licensed engineer or architect along with tax professionals. The IRS specifically prefers engineering-based studies over estimates or rules of thumb. Look for firms that follow the IRS Cost Segregation Audit Techniques Guide methodology.
Tenant improvements can be reviewed. Some qualifying interior improvements to nonresidential buildings are 15-year qualified improvement property, but exclusions, acquisition dates, and bonus-depreciation requirements must be checked for each asset.
No study guarantees an audit result. Ask how the provider documents asset classification, costs, inspection findings, and assumptions, and how it will support the report if the IRS examines it.
Tax law does not prescribe one professional credential, but a defensible allocation needs reliable records and sound methodology. Compare a desktop or engineering study based on the property and available documentation; avoid unsupported percentage rules.
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Glossary of Key Terms
Cost Segregation Study
An engineering-based analysis that identifies and reclassifies personal property assets and land improvements from real property for federal tax purposes, allowing shorter depreciation recovery periods and accelerated deductions.
Bonus Depreciation (Section 168(k))
An additional first-year deduction for eligible property. The law restored 100% for eligible property acquired after January 19, 2025; acquisition, placed-in-service date, and elections matter.
MACRS (Modified Accelerated Cost Recovery System)
The depreciation system used for most tangible property in the U.S. tax code. Assigns assets to specific recovery period classes (5, 7, 15, 27.5, or 39 years) with prescribed depreciation methods.
Section 1245 Property
Tangible personal property (equipment, furniture, fixtures) and certain intangible property. Upon sale, all depreciation taken on Section 1245 property is recaptured as ordinary income.
Section 1250 Property
Real property (buildings and structural components). Upon sale, depreciation in excess of straight-line is recaptured as ordinary income; remaining depreciation is subject to a maximum 25% 'unrecaptured Section 1250 gain' rate.
Qualified Improvement Property (QIP)
Generally an improvement made by the taxpayer to the interior of a nonresidential building after the building was first placed in service, excluding enlargements, elevators/escalators, and internal structural framework. Eligible QIP generally has a 15-year recovery period; bonus eligibility requires a separate check.
Look-Back Study
A study of property placed in service in a prior year. The correct method for any depreciation adjustment depends on the prior return and accounting-method rules.
Form 3115 (Change in Accounting Method)
IRS form used to request an accounting-method change. It may be relevant to some look-back studies; prior returns and current IRS procedures determine the filing route.
Section 481(a) Adjustment
A cumulative adjustment computed for an eligible accounting-method change. Its amount and treatment depend on the prior returns and the change being made.
Depreciation Recapture
When property is sold, previously claimed depreciation deductions are 'recaptured' and taxed. Section 1245 recapture is taxed at ordinary income rates. Section 1250 (real property) recapture is taxed at a maximum 25% rate.
Tangible Personal Property
Property that is not a structural component of the building, such as certain removable floor coverings, appliances, furniture, and equipment. Classification turns on function and attachment; an item does not become short-life property merely because it can be touched or removed.
Land Improvements
Improvements to the land surrounding a building, such as sidewalks, parking lots, landscaping, fencing, drainage systems, and outdoor lighting. These have a 15-year MACRS recovery period.
Placed in Service Date
The date property is ready and available for its intended use. It determines when depreciation begins; the acquisition date also matters for bonus depreciation.
IRS Audit Techniques Guide (ATG)
The IRS's internal reference document for auditing cost segregation studies. Published in 2004, it outlines quality standards, acceptable methodologies, and common issues. A properly performed study should follow the ATG framework.
What gets reclassified, and how much, varies a lot by building type. We keep a dedicated guide for each, with the typical asset breakdown, a worked example, and the other tax strategies that pair with a study for that kind of owner. Start at the property type hub or jump straight to your building:
A useful study decision combines provider scope, asset-level support, usable deductions, and a realistic sale scenario. Explore the cost segregation study service, or book a free 30-minute consultation with our team to discuss your needs, our services, fit, and next steps. Property analysis and personalized tax advice require a paid engagement.
See What a Study Could Do for Your Property
Engineered Tax Services performs the engineering-based study. Taxstra turns the report into actual tax savings on your return and coordinates the strategy around it. Start with their calculator or real case studies.
Disclosure: Taxstra may receive a referral fee if you engage Engineered Tax Services through links on this page. That relationship does not change your price, and it is not a recommendation for your specific situation.
