Commercial real estate cost segregation: is a study worth it for your building?

By CostSegregationMatch. Tax rules, prices and provider terms checked October 7, 2026.

Yes, cost segregation works on commercial real estate.

A commercial building is generally written off over 39 years under the standard federal depreciation system. A cost segregation study identifies costs that qualify for shorter lives, often 5, 7 or 15 years. Think carpet, wiring for specific equipment and qualifying site improvements. Each classification needs support. Land is not depreciable.

Eligible property acquired and placed in service after January 19, 2025 can qualify for 100% bonus depreciation. That can write off qualifying shorter-life costs in their first year. The study date does not reset those dates. Acquisition rules, prior ownership and tax elections also matter. The rules are in IRS Publication 946 and IRS Notice 2026-11.

A study is worth paying for when three things line up:

1. Enough of your building moves to shorter lives.
2. You can use the bigger deduction on your tax return.
3. The fee is small next to the tax you put off.

This page walks you through all three for offices, retail, warehouses, medical and dental buildings, hotels and self-storage.

Compare commercial study options

Or start here: find your property type, see the dollar example, or run your own numbers. You can read and compare everything on this page without giving us your contact details.

Start with your property type

Your property type tells a study provider where to look. It does not decide how much moves or who gets the deduction. Those depend on what you own and what your records show.

Find your row. The last column is the question to sort out before trusting an estimate.

These are things to look at, not promises. What an item is used for, how it is attached, who owns it, and what your records show decide the result. The general rules are in IRS Publication 946 and the IRS Cost Segregation Audit Technique Guide.

A quick test before you read on:

• Your tax preparer thinks you can use more deductions this year. Get an estimate for your building and a full fee. Compare the options.
• You are not sure you can use the deduction, or you may sell soon. Read Can you use the deduction? first.
• You own only land, or the property is for personal use. A study is not your next step. The IRS explains what can be depreciated.

How much of a commercial building can move?

We did not find an IRS-published average or an independent dataset that establishes a typical share for each commercial property type.

What does exist is what study providers publish about their own jobs. We checked 11 examples across these property types. "Share moved" means the part of the cost, after land, that the provider reports assigning to 5-, 7- or 15-year property. The software office example reports a different measure: total first-year depreciation.

Provider-published examples, checked October 7, 2026. Percentages are the providers' reported allocations or sums of their rounded class shares; they can differ slightly from ratios of the published dollar figures. The software office row reports total first-year depreciation, not a reclassification share, extra deduction or tax saving. We read the public pages, not the underlying studies.

For Wilmington, La Pine and Sebring, we calculated cost after land by adding the published class allocations.

How to read this table

• In the 10 examples that give a share, it runs from 23.9% to 59.88%.
• These are selected promotional examples, not a random sample of completed studies. Yours could land lower.
• Ten of the 11 come from one firm. This is a look at what gets published, not a benchmark.
• The spread inside one property type can be bigger than the gap between types. The two self-storage examples are 25.58% and 59.88%.

How we chose them. We selected public examples covering all six property types: 10 allocation examples and one software example reporting first-year deductions. We read the full pages and checked their arithmetic where dollar amounts were supplied. We excluded a warehouse example whose asset totals did not reconcile to its stated basis. We did not independently verify the studies or their classifications.

Two more numbers you may run into:

• R.E. Cost Seg says its full studies deliver first-year depreciation that is "often 25–50% of the building's value." That is the company's own claim, from its study page.
• In a September 2018 Inside Self-Storage article, Heidi Henderson, executive vice president of Engineered Tax Services, described reclassification percentages from 15% to as high as 40%. This is a historical provider-authored statement, not an independent benchmark. Neither this range nor R.E. Cost Seg's claim is a forecast for your building.

What pushes your number up or down

• Finishes. Equipment and specialized fit-outs can add costs to examine, but a fitted-out building does not guarantee a higher percentage.
• Site work. Supported paving and other qualifying land improvements may add to the 15-year group. Their share depends on the whole property's basis.
• Ownership. Only costs in your depreciable tax basis belong in your study. Tenant-owned improvements are not automatically yours.
• What is already split out. Deductions already reflected in the existing schedule are not new benefits from the study.

What changes in dollars? A worked example

The number that matters is not the big deduction. It is the extra deduction compared with what you would get anyway, and how much of that extra you can use.

Here is one made-up building. It is not a customer result or an estimate for you.

The setup

These are hypothetical numbers, chosen to keep the math simple. The 20% is not an average for any property type. The $6,000 is not a quote from any provider.

This assumes a calendar-year taxpayer, standard 39-year depreciation under the General Depreciation System (GDS), and a qualifying unrelated purchase. The acquisition and service-date rules are met, all $480,000 qualifies for 100% bonus, and there is no election out. We assume no assets are already separately depreciated, no requirement to use the Alternative Depreciation System (ADS), and no Section 179, production-property allowance or other basis adjustment. The 32% is a constant assumed federal tax effect, not a forecast of your tax bracket.

The comparison starts with all $2.4 million on a 39-year schedule solely for this example. If your actual schedule already separates equipment or improvements, compare against that schedule instead.

First-year depreciation, with and without the study

How the building line works: a building placed in service in July gets 5.5 months of depreciation in year one. So $2,400,000 ÷ 39 years × 5.5 ÷ 12 months = $28,205. With the study, the building part is $1,920,000, which gives $22,564. Calculations using IRS percentage tables may differ slightly; figures are rounded for display. The method is in IRS Publication 946.

The same deduction, three different outcomes

"None of it" means no current tax benefit is assumed. A disallowed loss may carry forward, but whether and when it becomes usable depends on the limitation involved and later events. Paying the fee now does not guarantee a later cash benefit.

What you give up. You moved $480,000 out of the building group. So that building account has about $12,308 less depreciation in a later full year while this comparison still applies. Cost segregation moves deductions forward. It does not create new ones.

This example leaves out state tax, tax when you sell, and how the fee itself is treated. Ask your tax preparer to add those if they matter for you.

One more thing. This example building is too big for the self-guided software option below, which tops out around $1.5 million of cost after land.

Run your own numbers

Use the tool to explore an assumed first-year scenario. A provider estimate can supply proposed allocations; your tax preparer must confirm the asset lives, bonus rate, convention and amount usable. A guessed percentage is a hypothetical input, not a property estimate. The tool runs in your browser. The tool itself does not save or send your entries.

It separates 5-year and 7-year assets and 15-year land improvements. It assumes a full calendar year, 39-year GDS building depreciation and the half-year convention for the shorter-life assets. It does not model QIP, ADS, the mid-quarter convention, catch-up depreciation or tax when you sell. Do not use its results if those assumptions do not fit.

The tool does the same math as the example above. Choose "Use the example numbers" and you will see $28,205, $502,564 and $474,359.

Before relying on the result, check the deduction limits below with your tax preparer.

Can you use the deduction?

A study can be right and still do little for you this year.

One reason is the passive loss rules. Rentals are generally passive, and passive losses generally offset passive income. Exceptions may apply. A suspended passive loss usually carries forward; a full taxable sale of your entire interest to an unrelated buyer can release it. A partial sale or exchange does not automatically do that. Basis, at-risk and other loss limits can also affect what you use. The rules are in IRS Publication 925.

Find your situation:

The special rental-loss allowance generally falls by 50 cents for each dollar of modified adjusted gross income above $100,000 and reaches zero at $150,000. For married people filing separately who lived apart all year, the maximum is $12,500 and the phaseout runs from $50,000 to $75,000. Married people filing separately who lived together at any point in the year cannot use it. Active participation and ownership requirements also apply. IRS Publication 925 explains the tests.

A few terms, in plain words:

• Real estate professional. You perform more than half your personal services in trades or businesses, and more than 750 hours, in real property trades or businesses in which you materially participate. Employee work generally counts only if you own more than 5% of the employer. On a joint return, one spouse must meet these tests independently. A study does not make you one.
• Materially participate. You meet one of the IRS participation tests for the activity. Regular involvement alone is not enough to assume you pass.
• Excess business loss limit. A separate limit for noncorporate taxpayers, applied after other relevant loss limits. For tax years beginning in 2026, the threshold used to calculate it is $256,000, or $512,000 on a joint return. It is not a per-property depreciation limit. IRS Rev. Proc. 2025-32.

A savings estimate that only multiplies the deduction by a tax rate has skipped this step. Ask your tax preparer to compare your tax with and without the extra deduction.

When to pause before you pay

What does a commercial cost segregation study cost?

It depends on who does the work. We checked two published commercial options today. One is software you run yourself. The other is a full study done for you.

These are a published example and a starting fee. They are not quotes for the same building, and they are not a market average.

Provider-published prices and terms, checked October 7, 2026. Confirm the scope and final fee with the provider before you order.

See software pricing

Request a proposal from R.E. Cost Seg

These are unpaid editorial links as of October 7, 2026. You choose if and when to contact a provider. The proposal form on R.E. Cost Seg's site asks for your name and email. How we make money.

Which one fits?

• A smaller, simple building you bought, on the software's list, under the size limit. Look at the software with your tax preparer.
• A larger or complex building, a retail or medical property, new construction, a big renovation, or thin records. Ask for a full-study proposal.
• You want someone else to do the work. Ask for a full-study proposal.

Ask for the total. A starting fee is not the bill. Ask what your building costs with the inspection, any changes, rush work and tax forms included. One piece of math, so you can see how add-ons stack: $2,730 plus the $600 Form 3115 add-on is $3,330. That is not a quote, and you may not need the form.

What does "audit support" cover?

The scope varies. Read what is included and excluded.

Neither one is a promise that you will not be audited. An "IRS-compliant" label is not IRS approval of a provider or its report. The IRS audit guide is examination guidance, not a provider-approval program.

Want all three offers we currently compare, including residential options?

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What changes by property type?

One rule sits above all of these. Only costs in your depreciable tax basis belong in your study. If a tenant paid for a build-out and owns it, it belongs on the tenant's books. When you buy a building, confirm which improvements you acquire and what cost belongs in your tax basis. Existing tenant-owned assets do not automatically become yours.

These lists identify costs to examine, not automatic tax classifications. Permanent cabinets, ordinary plumbing and other structural components may remain building property. Later taxpayer-made improvements may have different treatment under the QIP rules or Section 179 rules below. See IRS Publication 946 and the IRS audit guide.

Office buildings and office condos

What may move: carpet, cabinets and millwork, decorative lighting, data cabling, circuits that serve specific equipment, break-room cabinets and plumbing. Outside: parking, sidewalks, landscaping.

Usually treated as building property: the structure, roof, windows, general lighting, building-wide heating and cooling, main plumbing, elevators.

Example: You buy a multi-tenant office. Your tenants own their desks and computers. Those are not part of your study. The proposal should show what is in your purchase and how landlord-paid build-outs are recorded.

Published examples: 27.65% moved in one Engineered Tax Services study. KBKG reports $218,000 of first-year deductions on a $1.2 million office from its software.

Ask: "Which tenant build-outs came with the building, and which belong to tenants?" For an office condo, ask which shared areas are in your cost.

Retail buildings and shopping centers

What may move: signs, display and accent lighting, special finishes, wiring for specific equipment. Outside: parking fields, curbs, pylon signs, site lighting.

Usually treated as building property: the shell, roof and storefront glass.

Example: You buy a strip center. The restaurant tenant's kitchen equipment and the clothing store's display racks do not come with it. A provider should read the leases before counting those costs.

Published examples: 30.35% and 36.83%.

Ask: "On my leases, what did the tenants build and own?"

Good to know: the IRS audit guide includes charts for retail, restaurants and auto dealerships. They discuss classifications for common items. The charts are examination guidance for specific facts, not automatic classifications for every property.

Warehouses and industrial buildings

What may move: power and piping that serve equipment, racking you own that is not part of the structure, finishes in the office area. Outside: truck courts, paving, fencing, drainage.

Usually treated as building property: the shell, slab, roof and general lighting.

Example: You own a warehouse. Your tenant owns the racking and conveyors. Those cannot be added to your cost.

Published example: 31% in the Pearland warehouse-and-office case above. That total does not establish a percentage for a plain warehouse shell.

Ask: "How much of this building is finished office, and how big is the paved yard?"

If you make things there: a separate rule for factories may apply. See qualified production property.

Medical and dental buildings

What may move: cabinets and casework, and the plumbing, vacuum, air and electrical lines that serve chairs and equipment. Outside: parking and landscaping.

Usually treated as building property: the shell and the general plumbing, electrical, heating and cooling.

Example: A dentist leases a suite and pays for the operatory build-out. The study is about the dentist's improvements and equipment, not the whole building. If a separate company owns the real estate, both sets of records need to line up.

Published examples: 43.5% and 45.49%.

Watch for double counting. Chairs, x-ray units and sterilizers are equipment. If your practice already writes them off, they are not new deductions.

Ask: "My practice rents from my own company. Does the self-rental rule trap this loss?"

Hotels and motels

What may move: room furniture, carpet, decorative lighting, laundry and kitchen hookups. Outside: parking, pool decks, signs.

Usually treated as building property: the structure, elevators and most building systems.

Example: Your purchase contract already puts a value on beds, TVs and laundry machines. A later study should start from that split. Otherwise it takes credit for deductions you already have.

Published examples: 23.9% and 24.36%.

Good to know: the residential-rental definition excludes hotels and similar establishments where more than half the units are used on a transient basis. Such hotel buildings are generally 39-year nonresidential property under GDS. A mostly long-stay property needs a separate review of the residential-rental tests. This is different from the seven-day passive-loss rule above. IRS Publication 527 has the definition.

Ask: "Is the furniture already on my books apart from the building?"

Self-storage

What may move: gates, security systems, fencing, paving, drainage and site lighting. The published Sebring example also assigns some unit partitions and roll-up doors shorter lives; that is a classification to verify, not a rule for every facility.

Usually treated as building property: permanent storage buildings and structural components.

Published examples: 25.58% and 59.88%. The historical 15% to 40% statement above also comes from an Engineered Tax Services author.

Why the published results differ. La Pine's page allocates 25.58% to 15-year site improvements and keeps its storage unit doors in the 39-year group. Sebring's page reports 34.45% in 5-year assets, 11.13% in 7-year items such as unit partitions and roll-up doors, and 14.30% in 15-year improvements; its building shell remains in the 39-year group. These public summaries do not establish the whole reason for the gap. Ask for the item-by-item classifications and the authority supporting them.

Ask: "How are you classifying the storage buildings, and what supports it?"

Mixed-use and other commercial property

A building with shops below and apartments above is not classified by a simple square-footage split. Residential rental property generally requires at least 80% of gross rental income for the tax year to come from dwelling units. If you live in part of the building, the test includes its fair rental value. Have your tax preparer apply the definition and any exclusions before choosing 27.5-year residential or 39-year nonresidential GDS treatment. IRS Publication 527 explains the test.

Restaurants, auto dealerships, car washes and other special-use buildings follow the same steps: what do you own, what does it do, and what do your records show.

For apartments and other residential rentals, see the full comparison of study options.

The federal rules that set your number

Acquisition and service dates set the bonus rate

A study sorts your building into groups. Bonus depreciation decides how fast you write off the shorter-life groups. The rate follows the tax acquisition date and the placed-in-service date—the date it is ready and available for its intended use.

These are general rates for otherwise eligible ordinary property, before elections. The earlier-year rows assume a qualifying acquisition after September 27, 2017. Long-production-period property and certain aircraft have different transition rules. Your tax preparer must apply contract, construction and other eligibility rules.

A signed contract is not always the final tax acquisition date. Enforceability, cancellation periods, contingencies and construction rules can matter. Elections can also change the result, including a limited 40% transition election for the first tax year ending after January 19, 2025.

The 100% rate and the January 19, 2025 date come from IRS Notice 2026-11 and the IRS announcement. The earlier rates are in IRS Publication 946.

Three things to know:

• Certain used property counts. You do not have to be the first owner. Related-party purchases, a prior depreciable interest and carryover-basis transactions can prevent bonus treatment. Prior use as a tenant is not by itself the same as a prior depreciable interest. See Treasury Regulation 1.168(k)-2, applied with Notice 2026-11.
• The ordinary building shell does not get Section 168(k) bonus. The shorter-life assets still have to meet the bonus requirements. The separate production-property rule below is different.
• Later improvements get their own dates. A 2026 renovation on a 2022 building is looked at on its own.

What a different rate does to the math: at 100% bonus the example's extra first-year deduction was $474,359. To isolate the rate's effect, suppose the same basis instead qualified for 40% bonus, with $288,000 classified as 5-year property and $192,000 as 15-year land improvements. Assuming the half-year convention, 200% declining balance for the 5-year assets and 150% declining balance for the land improvements, the extra first-year deduction would be $226,679—less than half. This is a separate hypothetical rate scenario, not an alternative rate automatically available for the July 2026 purchase above.

Renovations and "qualified improvement property"

Qualified improvement property, or QIP, generally means an interior improvement you make to a nonresidential building, placed in service after the building was first placed in service by anyone. It is generally 15-year straight-line property under GDS, or 20-year straight-line under ADS. Eligible QIP under GDS can qualify for bonus depreciation. IRS Rev. Proc. 2020-25 explains the recovery periods and methods.

It does not include making the building bigger, elevators or escalators, or the internal structural frame.

One condition matters here. QIP has to be made by you. When you buy a building, the last owner's interior work does not become your QIP. The definition is in Treasury Regulation 1.168(b)-1.

Example: You buy an office, then redo the interior the next year. Keep the renovation costs apart from the purchase and from equipment. That way nothing is counted twice.

Tearing things out? If your renovation removes old parts of the building, ask your tax preparer about writing off what is left of their cost. The partial-disposition election generally belongs on a timely filed original return, including extensions, for the year the component is disposed of. Ask before filing; eligibility and limited relief rules need review. Treasury Regulation 1.168(i)-8.

Did you elect out of the business interest limit?

Some real property businesses elect out of the Section 163(j) business-interest limit. That does not remove every other restriction on interest deductions. The trade-off is ADS depreciation for nonresidential real property, residential rental property and QIP held in the electing business. Those assets cannot receive Section 168(k) bonus.

The election does not strip bonus from every item a study finds. But tell your tax preparer about it before you trust any estimate. The IRS explains the election here.

Section 179

Section 179 is another way to deduct eligible costs in the first year. For tax years beginning in 2026, the maximum is $2,560,000. It is reduced dollar for dollar by qualifying property placed in service above $4,090,000. These are taxpayer-level limits, not a fresh allowance for each building. IRS Rev. Proc. 2025-32.

You can elect to include qualifying QIP and eligible improvements to roofs, heating and cooling, fire-protection and alarm systems, and security systems in a nonresidential building after it was first placed in service. Business-use, purchase and other conditions apply, including special restrictions for noncorporate landlords. Unlike bonus, Section 179 has a taxable-business-income limit; amounts disallowed by that limit may carry forward. Ask your preparer which route fits. IRS Publication 946 covers it.

Factories: qualified production property

The 2025 tax law added a special 100% write-off for some factory buildings. It has tight rules:

• Construction generally has to start after January 19, 2025 and before January 1, 2029.
• The eligible property must be placed in service after July 4, 2025 and before January 1, 2031.
• Office space and finished-goods storage inside the building are generally left out, subject to limited de minimis rules.
• A landlord whose tenant does the manufacturing generally does not qualify.

This is an election for eligible U.S. property used as an integral part of a qualifying manufacturing, production or refining activity, with additional use and ownership rules. Certain acquired existing property has a separate route. Limited commonly controlled landlord-and-operator arrangements may also qualify.

An ordinary warehouse does not qualify just because it is industrial. If you make things in a building you own, ask your tax preparer and your study provider if this belongs in the scope. The interim rules are in IRS Notice 2026-16.

What happens when you sell, and other trade-offs

You are moving deductions, not making new ones. More now means less later. In the example, the building account has about $12,308 less depreciation in a later full year while the comparison still applies.

Selling changes the math. When you sell, part of your gain is tied to the depreciation you took.

• For Section 1245 assets, gain is generally ordinary income up to depreciation allowed or allowable, limited by the gain. That includes bonus depreciation.
• Section 1250 assets follow different rules and may also require ordinary-income recapture for depreciation above straight line. For individuals, the part called unrecaptured Section 1250 gain can face a maximum 25% federal rate. That is not a 25% ceiling on every building-related tax or every gain. A short recovery period alone does not tell you which section applies.

A study can change the mix of assets and the character of gain when you sell. A short hold can reduce the time value of getting deductions early, but it does not automatically make a study worthwhile or worthless. Ask your tax preparer to allocate the sale proceeds among assets and model your planned hold and an earlier sale. IRS Publication 544 covers sales; IRS Topic 409 explains the 25% category.

You do not have to keep buying property because you ordered a study. An exchange can put off some tax, but not every item in a study is treated the same. The like-kind exchange rules generally apply to qualifying real property, and recapture rules can still matter. Ask before you exchange. IRS Publication 544 explains the limits.

Your state may not follow along. A federal deduction is not automatically the state deduction. For example, California's 2025 corporation instructions identify nonconformity with Section 168(k) bonus and the new Section 168(n) allowance. Ask your preparer to calculate the rules for your state and entity separately. California FTB instructions.

Audits. The IRS has a written guide for examining these studies. It looks at support: how costs were split, what records back them up, and whether the totals tie to what you paid. We found no IRS-published audit rate for cost segregation, so we do not quote one.

Timing, older buildings, and the records you need

Talk about scope before a tax deadline is close. If you plan to renovate, ask how the purchase, the new work and the torn-out parts will be recorded before the evidence is gone.

You already own the building. Is it too late?

No. You can do a study on a building you have owned for years.

An eligible accounting-method change can bring previously underclaimed depreciation into a Section 481(a) adjustment, often using Form 3115. A negative adjustment is generally taken in the year of change. Some corrections instead use an amended return or another procedure. Your tax preparer must decide which applies. IRS Publication 946.

Three things to know:

• Historical acquisition and service dates control the bonus rules, not the year of the study. Prior elections also matter. See the table above.
• The study and the form are often separate fees. R.E. Cost Seg lists Form 3115 preparation at $600 per study. CostSegregation.com produces the catch-up number but does not file the form.
• Your tax preparer decides the right filing. A web page cannot.

Records to gather

1. Closing statement and purchase contract
2. Whatever supports your land value, like an appraisal
3. Your current depreciation schedule, and any earlier study
4. Leases, and records of who paid for and owns each build-out
5. Construction or renovation ledgers, invoices and contracts
6. Plans, site drawings, photos and equipment lists
7. The dates you bought, built, improved and started using the property
8. Your plans: renovations, a possible sale, and your filing deadline

Missing plans or invoices? A provider may be able to work from other records and estimates. Ask what method it will use and what the limits are.

Do not send tax returns or property records to us. They go to your provider and your tax preparer.

What a good commercial study includes

Compare how well the report documents your building, not the size of the promised deduction.

Do you need an engineer or a site visit? The IRS audit guide does not prescribe a single study format or a single required preparer credential. It describes a quality study as accurate and well documented and discusses site visits as part of developing a study. Ask how the inspection method and records support the assets in your report. The guide is for IRS examiners. It is not an approval program.

See how we compare study offers.

Your commercial study brief

Use this with a study provider and with your tax preparer. Fill in what you know. Leave the rest as "Please help confirm."

You can copy or print it. The brief tool itself does not save or send your entries. Copy or print before you leave the page.

Prefer a plain file? Download the brief as a text file.

Download the brief (.txt)

Ready to send it to a provider? Compare commercial study options.

Other questions before you choose

Is there a minimum property value for commercial cost segregation?

There is no general federal minimum property value for a cost segregation study. The depreciation rules in IRS Publication 946 turn on eligible property and tax basis, not a universal study-price threshold. Rules of thumb about building value are commercial screening criteria.

What matters is the math. How much moves, how much of it you can use, and what the study costs. A software limit or a firm's minimum job size is about its product, not about the law.

Can my CPA do this without a study company?

Sometimes. If your costs are already detailed and your CPA knows the rules, they may be able to split out items without an outside report. Ask your CPA what extra construction or cost work would be needed. The IRS guide does not require one type of provider.

Does it work on a triple-net leased building?

Yes, a triple-net lease does not by itself prevent a study. Include only costs in your depreciable tax basis. Tenant-owned improvements are not automatically yours, and site work still needs the correct classification. Rental losses are generally passive, so check whether you can use them. See IRS Publication 946 and Publication 925.

What if I got the property through an exchange, inheritance or gift?

Start with your tax preparer. Your cost for tax purposes may not be what the property is worth, and bonus depreciation may not apply the way it does in a normal purchase. Give the provider your confirmed cost and the history before you order.

Do I need a separate study for each building?

Ask for a written scope that names each property. One percentage should not be copied across different buildings without support. If a provider wants to study a sample and apply it to the rest, ask why that fits and how it handles the differences.

Does a study raise my audit risk?

We did not find an IRS-published audit rate specific to cost segregation. R.E. Cost Seg reports that fewer than 0.1% of its studies have been audited, but its service page does not publish the underlying dataset or reporting period. That company claim does not establish your audit probability or show whether ordering a study changes it. What you can control is the support behind your study.

How we checked this page

• Tax rules. We checked them against IRS publications, notices and Treasury regulations. Each source is linked next to the claim it supports.
• Prices and terms. They come from the providers' own pages. We read them on October 7, 2026.
• Study examples. We read the providers' public pages and recalculated the published figures. We did not buy, test or review the underlying studies.
• The worked example. It uses made-up numbers that we state in full. It is not a customer result.
• Expert review. No CPA or engineer has reviewed this page. If that changes, we will name the reviewer and what they reviewed.

Found something wrong? Send a correction. See our editorial standards.

Your next step

Start with what you own. Ask your tax preparer how much of the extra deduction you could use. Then compare a written scope and fee.

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Or go back to the two commercial options on this page.