Cost Segregation FAQ: 100 Most Common Questions Answered

A cost segregation study is an engineering-based analysis that reclassifies between 20% and 40% of a real estate purchase price out of 27.5-year (residential) or 39-year (nonresidential) depreciation and into 5, 7, and 15-year recovery periods. Combined with 100% bonus depreciation under OBBBA for property acquired and placed in service after January 19, 2025, this produces large first-year tax deductions.

WeCostSeg pricing is transparent and competitive: Rapid Reports from $795 for residential properties under $800K depreciable basis, Fully Engineered Residential studies from $2,495, and Fully Engineered Commercial studies from $2,995. All studies include 5 years of audit defense at no extra charge. Get a free written proposal in 24 hours.

Generally yes when three conditions are met: depreciable basis above $300K, your property qualifies for 100% bonus depreciation (placed in service after January 19, 2025), and you have a way to use the losses (Real Estate Professional Status, the short-term rental loophole, or passive income to offset). Our 3-Bucket Decision Framework page walks through each scenario.

Yes. A look-back cost segregation study captures missed depreciation from prior years. You file Form 3115 (Designated Change Number 7) with your current return and take the entire Section 481(a) catch-up adjustment in the year of change. No amended returns are required. Rev. Proc. 2022-14 provides the automatic procedure.

Rapid Reports typically deliver in 5-10 business days. Fully Engineered studies typically deliver in 15-20 business days after we receive all documentation and complete the inspection. Rush turnaround is available for tax deadlines.

Cost segregation studies do not trigger audits when properly conducted. The IRS published its Cost Segregation Audit Techniques Guide (Publication 5653, updated February 2025) which describes how examiners review studies. Properly engineered studies that document the 13 Principal Elements of a Quality Study rarely face challenges. We include 5 years of audit defense with every study.

A WeCostSeg report includes the engineer's qualifications, methodology disclosure aligned to IRS Pub 5653, property description, detailed asset listings with cost basis and recovery period for each component, supporting photographs and documentation, IRC and Treasury regulation citations, and a depreciation schedule in both PDF and Excel format for your CPA.

Any income-producing property placed in service after 1986 qualifies. This includes single-family rentals, multifamily, short-term rentals (Airbnb, Vrbo), office buildings, retail, industrial warehouses, hotels and motels, restaurants, self-storage, medical and dental offices, gas stations, and agricultural buildings.

It depends on the study type. Rapid Reports use questionnaire data and existing documentation without a site visit. Fully Engineered studies typically include either a virtual site inspection (smartphone video walkthrough with an onsite contact) or an in-person inspection for larger commercial properties.

Software-driven DIY tools exist for smaller residential properties, but they have meaningfully different audit defense profiles than engineered studies. For most properties above $500K basis, the savings from a proper engineered study substantially exceed the fee difference. Our DIY vs Engineered comparison page details the tradeoffs.

First-year deductions typically range from 20% to 35% of depreciable basis. On a $1M building basis, that translates to $200K-$350K in first-year deductions. At a 35% combined federal and state marginal rate, the first-year tax savings are roughly $70K-$120K. Use our savings calculator for an estimate specific to your property.

Rapid Reports rely on questionnaire data and standardized component allocations. Fully Engineered studies include actual cost record review, blueprint analysis, and site inspection. The IRS Cost Segregation Audit Techniques Guide identifies six methodologies; the detailed engineering approach from actual cost records is the most defensible.

Yes. The fact that you do not own the dirt does not matter for the building component reclassification. Your condo purchase price includes interior components (cabinets, flooring, appliances, electrical fixtures) and a share of common area improvements, all of which can be reclassified.

Yes, but the basis is generally the fair market value at the date of death (the stepped-up basis under Section 1014). A cost seg study uses the stepped-up basis as the starting point for reclassification.

Yes. Cost segregation studies are entity-agnostic. The pass-through depreciation flows to your K-1 and your individual return.

On a $500K basis property with 25% reclassification and 100% bonus depreciation, expect roughly $125K in additional first-year deduction. On a $1M basis, roughly $250K. On a $2M basis, roughly $500K.

Yes, and we coordinate directly with them. Our CPA Coordination Protocol involves three touches: preliminary analysis shared before engagement, draft report shared for CPA review before finalization, and Form 3115 coordination if a look-back study is involved.

Sometimes. The math gets tighter at lower basis levels because the study fee remains roughly constant while the deduction lift scales with basis. For a $250K basis STR with 25% reclassification at 100% bonus and a 32% combined marginal rate, you save roughly $20K against a $795 Rapid Report fee. Still positive, but tighter than larger properties.

No. Cost segregation uses the US Internal Revenue Code, MACRS, and IRS depreciation rules. Foreign-located property uses the Alternative Depreciation System (ADS), which does not benefit from cost seg or bonus depreciation.

Cost segregation accelerated personal-property deductions are subject to Section 1245 ordinary-income recapture at sale. If you plan to sell within 2-3 years, cost seg may still pencil but the recapture cost reduces the net benefit. A 1031 exchange defers all recapture into the replacement property.

Under the One Big Beautiful Bill Act (OBBBA, Public Law 119-21, signed July 4, 2025), bonus depreciation is permanently restored at 100% for qualified property acquired and placed in service after January 19, 2025. Property acquired before January 20, 2025 under a written binding contract remains on the prior phase-down schedule.

The cutoff is January 19, 2025. If the binding contract to acquire your property was entered into on or before January 19, 2025, the prior phase-down rates apply: 40% for 2025 placement, 20% for 2026, 0% thereafter. If the binding contract is dated after January 19, 2025, 100% bonus applies for property placed in service after that date.

A binding contract is one that is enforceable under state law and does not limit damages to a specific amount. Letters of intent, options, and contracts with liquidated damages clauses generally do not qualify as binding contracts. Closing date is irrelevant; the binding-contract date controls.

Taxpayers may elect 40% bonus depreciation (60% for long-production-period property and certain aircraft) for the first taxable year ending after January 19, 2025. This is a one-time election useful for managing the loss size, avoiding wasted NOLs, or aligning with passive income capacity.

Yes. Under Section 168(k) as amended by TCJA and continued under OBBBA, used property qualifies for bonus depreciation if it is the taxpayer's first use of the property, it was not acquired from a related party, and there is no carryover basis.

Section 168(n), added by OBBBA, allows a 100% deduction on certain nonresidential real property used in qualified production activities. Construction must begin after January 19, 2025 and before January 1, 2029, and the property must be placed in service before January 1, 2031. IRS Notice 2026-16 provides interim guidance.

Yes. You can elect out of bonus depreciation by asset class on a per-year basis. The election applies to all qualified property in that class for that year. Once made, the election is generally irrevocable without IRS consent.

Yes. Section 179 expensing is applied first (up to the cap, with phaseout), then bonus depreciation on the remaining basis, then regular MACRS. OBBBA expanded Section 179 to a $2.5M cap with a $4M phaseout threshold.

Qualified Improvement Property (QIP) is interior improvement to nonresidential real property placed in service after the building's original placement in service. QIP has a 15-year recovery period under Section 168(e)(6) and is bonus-eligible. Under OBBBA's 100% bonus, QIP placed in service after January 19, 2025 is fully deductible in year one.

Permanently. OBBBA made the 100% bonus depreciation rate permanent, eliminating the prior phase-down schedule for qualifying property acquired and placed in service after January 19, 2025.

Yes. Land improvements (paving, fencing, landscaping, parking lots) are 15-year Section 1250 property and are bonus-eligible. Land itself does not depreciate.

No. Bonus depreciation applies only to property used in a trade or business or held for investment. A personal residence does not qualify. Converting a primary residence to a rental triggers basis-allocation rules and the property becomes bonus-eligible thereafter for the depreciable portion.

Bonus depreciation rules for the replacement property are complex. The replacement property's basis-carryover portion is generally not eligible for new bonus depreciation on that portion, but any boot (excess basis) is bonus-eligible. Reg. 1.168(k)-2(b)(3)(iv) provides the framework.

It varies. As of late 2025, only about 18 states fully conform. California, New York, New Jersey, Massachusetts, Connecticut, and many others require depreciation addback modifications that reduce or eliminate the state-level bonus benefit. Texas, Florida, Tennessee, Nevada, Washington, Wyoming have no state income tax or franchise tax that uses bonus. Check our state pages.

IRS Notice 2026-11, released January 14, 2026, provides interim guidance on bonus depreciation under amended Section 168(k) following OBBBA. It clarifies the acquisition date rules, binding contract definitions, and the 40% election mechanics.

Yes. Bonus depreciation can produce a net operating loss for individuals and entities. The NOL is subject to the post-TCJA limitations: it cannot be carried back (except for farming losses), and the NOL carryforward is limited to 80% of taxable income in any future year.

Yes, with caps. Heavy SUVs (over 6,000 lbs GVWR) used more than 50% for business have no luxury auto cap under Section 280F. Passenger autos are subject to the Section 280F luxury auto limits even with bonus.

Section 179 is an annual election with caps ($2.5M cap, $4M phaseout under OBBBA) and is limited to taxable income (cannot create a loss). Bonus depreciation has no cap, applies automatically (unless elected out), and can create a loss. Section 179 is typically used first because it's more flexible at lower levels; bonus picks up everything above.

Property with a recovery period of more than 20 years (most real estate building shell), property used predominantly outside the US, property used by tax-exempt entities, and certain regulated public utility property.

If you elect 40% instead of 100% for the first tax year ending after January 19, 2025, your cost seg study's reclassified 5/7/15-year property gets 40% bonus instead of 100%. This is useful when 100% would produce a wasted loss (e.g., insufficient income to absorb, NOL carryforward already large).

The STR loophole refers to Reg. 1.469-1T(e)(3)(ii) which excludes from the definition of 'rental activity' any property where the average period of customer use is 7 days or less. Because it is not a rental activity, losses are not automatically passive, and material participation under one of the seven Reg. 1.469-5T tests allows losses to offset non-passive income including W-2 wages.

If the average period of customer use across all guests for the tax year is 7 days or less, the activity is excluded from the rental activity classification. The calculation is total days rented divided by number of separate guest stays.

Sum the number of days each guest stayed, then divide by the total number of guests. Example: 50 guests staying an average of 4 nights each = 200 nights total / 50 guests = 4.0 average period of customer use. Anything 7.0 or below qualifies.

No. The STR loophole does not require REPS. You only need to materially participate in the STR activity itself under one of the seven Reg. 1.469-5T tests, the most common being 500+ hours or 100+ hours and more than anyone else.

From Temp. Reg. 1.469-5T(a): 500-hour test, substantially-all-work test, 100-hour-and-more-than-anyone-else test, significant participation activities aggregating 500+ hours, 5-of-prior-10-years material participation, personal service activity material participation in any 3 prior years, and the facts and circumstances test.

Yes. If you use a property manager who works more hours than you do, you fail the 100-hour and more-than-anyone-else test. You can still pass the 500-hour test or substantially-all-work test if those apply.

If the average period of customer use is 7 days or less, the property is nonresidential and depreciates over 39 years. Most CPAs miss this because they default to 27.5-year residential. Reference: former Reg. 1.167(k)-3, IRS Chief Counsel Advice 202151005, and standard accounting under Treas. Reg. 1.469-1T.

Yes, if the grouping is appropriate under Reg. 1.469-4. STR properties with similar economic characteristics can often be grouped, which helps you aggregate hours to pass the material participation tests.

Contemporaneous logs with date, hours, and activity description. Photographs, receipts, calendar entries, and email records all support the log. The Moss v. Commissioner, 135 T.C. 365 (2010) case held that vague self-reported hours without contemporaneous documentation can be rejected.

Yes, if you qualify under the STR loophole. Because the STR is not a rental activity under Reg. 1.469-1T(e)(3)(ii), losses from material participation are non-passive and offset wage income, interest, dividends, and other ordinary income.

Then your activity is a rental activity subject to the passive activity loss rules under Section 469. You need REPS to deduct losses against non-passive income, or you need other passive income to absorb the losses.

Hours by a co-host (your spouse or a partner) count toward the activity's total hours when checking the 'more than anyone else' test, but only your hours count toward your personal 500-hour or 100-hour test.

The Augusta Rule (Section 280A(g)) allows you to rent your personal residence for up to 14 days per year tax-free. It is unrelated to the STR loophole, which applies to investment properties classified as a trade or business.

Yes. Cost segregation on an STR can reclassify 25-35% of basis into 5/7/15-year property. Combined with 100% bonus depreciation and the STR loophole material participation, this often produces a first-year deduction large enough to wipe out significant W-2 income.

Each property is evaluated separately unless grouped under Reg. 1.469-4. You can pass material participation on self-managed properties and fail on PM-managed properties; the losses from the failing properties would be passive.

Real Estate Professional Status (REPS) is a designation under Section 469(c)(7) that exempts a taxpayer's rental real estate activities from automatic passive activity classification. To qualify, you must spend more than 750 hours and more than half of all your personal services in real property trades or businesses.

The 750-hour test requires that you perform more than 750 hours of services during the year in real property trades or businesses in which you materially participate. Spouse hours do not combine for this test, but each spouse can qualify independently.

The more-than-half test requires that more than 50% of all your personal services in trades or businesses during the year are in real property trades or businesses. If you have a 2,000-hour W-2 job, you need more than 2,000 hours in real estate to satisfy this test.

Section 469(c)(7)(C) lists 11: real property development, redevelopment, construction, reconstruction, acquisition, conversion, rental, operation, management, leasing, and brokerage.

Yes. The more-than-half test is the single most common failure point. Full-time W-2 employees typically work 2,000+ hours and must therefore document more than 2,000 hours in real estate to qualify.

Yes. Either spouse can qualify on their own hours. For the material participation portion (the third element of REPS), spouse hours do combine. Filing a joint return allows you to use the qualifying spouse's REPS status to apply to all jointly-owned rentals.

The aggregation election treats all of your rental real estate activities as a single activity for material participation testing. Without aggregation, you must materially participate in each rental separately, which is usually impossible. With aggregation, you only need to materially participate across the combined portfolio.

A licensed real estate agent's brokerage hours count toward both the 750-hour test and the more-than-half test, which often makes qualification easier. The agent still must materially participate in their rental activities (typically via the aggregation election).

Generally no. CPAs, mortgage brokers, lenders, real estate appraisers, and real estate-adjacent professionals typically do not qualify because their services are not in one of the 11 listed real property trades or businesses under Section 469(c)(7)(C). The IRS has been firm on this in audit and Tax Court.

If you are an employee of a real property business, your hours count toward REPS only if you own more than 5% of the business under Section 469(c)(7)(D)(ii). This prevents employees of large brokerages from claiming REPS without ownership.

No. Reg. 1.469-5T(f)(2) excludes investor activities (researching, reviewing financial statements, monitoring) from material participation hours. The Moss v. Commissioner case held that 'on-call' time without actual activity does not count.

Reg. 1.1411-4(g)(7) provides a safe harbor for real estate professionals: rental income is exempt from the 3.8% Net Investment Income Tax if you participate more than 500 hours per year in the rental activity, or did so in 5 of the prior 10 years.

Contemporaneous time logs, calendar entries, email records, receipts, photos of work performed, vendor invoices, and any documentation that verifies the time and nature of the activities. Self-reported retrospective summaries are routinely rejected in audit.

Yes. REPS is determined annually. You can qualify in 2025, fail in 2026, and qualify again in 2027. Each year stands on its own.

Suspended passive losses from prior years are released when you dispose of the underlying property in a fully taxable transaction. REPS does not automatically release prior suspended losses; it just makes current-year losses non-passive.

Rapid Reports from $795 for residential properties under $800K depreciable basis. Fully Engineered Residential studies from $2,495. Fully Engineered Commercial studies from $2,995, scaling with property size and complexity. All studies include 5 years of audit defense.

An engineer-reviewed cost segregation report based on questionnaire data and standardized component allocations for the property type. Includes a depreciation schedule in PDF and Excel, methodology disclosure, and 5 years of audit defense. Suitable for residential properties under $800K depreciable basis.

When your property exceeds $800K depreciable basis, has significant capital improvements or renovations, is a commercial or special-purpose property, or when audit risk is elevated. Fully Engineered studies use actual cost record review, blueprint analysis, and site inspection.

Yes. Submit your property details via WhatsApp or the free proposal form and we deliver a preliminary analysis within 24 hours showing estimated first-year deduction lift, estimated tax savings, recommended study type, and a fixed-price proposal. No obligation.

Yes. We perform look-back studies and prepare the accompanying Form 3115 (Designated Change Number 7) with the Section 481(a) catch-up adjustment. Pricing is the same as a current-year study because the engineering work is the same.

Yes. For look-back studies and other accounting method changes, we prepare both the original Form 3115 filed with the tax return and the duplicate filing sent to Ogden, Utah, as required under Rev. Proc. 2022-14.

Yes. Every WeCostSeg study includes 5 years of written audit defense covering methodology, asset classifications, and engineering conclusions. We respond in writing to IRS examiner inquiries at no additional charge. We do not represent clients in court or in formal IRS appeals.

Yes for Fully Engineered studies. We use virtual site visits (smartphone video walkthrough with an onsite contact) by default, with in-person visits available for large commercial properties or when virtual inspection is impractical.

Rapid Reports in 5-10 business days. Fully Engineered studies in 15-20 business days after we receive documentation and complete inspection. Rush turnaround in 5 business days is available subject to capacity.

We accept ACH, wire transfer, and credit card. Payment is due upon engagement signing. We can split commercial study fees into a 50% deposit and 50% on delivery for larger engagements.

Yes. Investors with 3+ properties or syndicators with portfolios receive discounted per-study pricing. Contact us via WhatsApp with your portfolio details for a custom proposal.

Yes. We will match any like-for-like written proposal from an ASCSP member firm or comparable engineering-led cost seg provider. Send the competing proposal via WhatsApp.

Yes, directly. Our CPA Coordination Protocol involves three handoffs: preliminary analysis to your CPA before engagement, draft report to your CPA for review before finalization, and Form 3115 coordination when needed.

We treat each property as a separate study with separate documentation. Portfolio pricing applies for 3+ properties. We can also produce a consolidated depreciation schedule across all properties for your CPA's convenience.

We do not guarantee specific dollar savings because every property is different. We do guarantee that our methodology meets the IRS Cost Segregation Audit Techniques Guide standards and that we will defend the study in audit at no additional charge.

IRS Publication 5653, the Cost Segregation Audit Techniques Guide, instructs IRS examiners on how to review cost segregation studies. The current edition (February 2025) covers methodology, the 13 Principal Elements of a Quality Study, industry-specific guidance, and audit procedures.

Chapter 4 of IRS Pub 5653 lists 13 elements: preparer credentials, methodology used, source data, written cost basis, classification of components, units of property, photo documentation, tax law and authoritative guidance, statement of preparer responsibility, audit defense provisions, identification of personal property and land improvements, treatment of structural components, and treatment of indirect costs.

Chapter 3 of the ATG describes six methodologies. The 'detailed engineering approach from actual cost records' is identified as the most accurate. Studies using rule-of-thumb allocations or non-engineered estimates have weaker audit defense.

AmeriSouth XXXII, Ltd. v. Commissioner (T.C. Memo 2012-67) is cited by IRS examiners to limit overly aggressive personal-property reclassifications. The case held that the taxpayer's cost seg study improperly classified certain HVAC and electrical components as personal property when they were structural.

An IRS examiner requests the study report, supporting documentation, photos, methodology, and preparer qualifications. The case may be referred to the LB&I Engineering Program for specialty review. Most audits resolve through documentation; few result in adjustments when the study is properly engineered.

Industry estimates suggest under 1% of properly engineered cost seg studies face IRS examination. R.E. Cost Seg has publicly reported under 0.1% audit rate across 15,000+ studies. We do not publish our own rate because we have not done 15,000 studies.

There is no IRS-mandated credential. The industry standard is the ASCSP Certified Cost Segregation Professional (CCSP) designation, which requires 7 years and 7,000 hours of direct cost seg experience. Engineers (PE, ME, EE), CPAs, and tax attorneys with cost seg experience are also acceptable per IRS Pub 5653 Chapter 4.

Yes. The syndication entity performs the study and the depreciation flows through to LP K-1s as ordinary loss. Whether the LP can use the loss depends on the LP's status (REPS, STR loophole, or passive income availability).

When a building component is replaced (roof, HVAC system, windows), a partial asset disposition election lets you write off the remaining basis of the replaced component. Cost segregation studies often identify dispositions retroactively.

Accelerated personal property is subject to Section 1245 ordinary-income recapture on sale (Form 4797). Unrecaptured Section 1250 gain on the real-property portion is capped at 25%. 1031 exchange defers all recapture into the replacement property's basis.

States vary widely. About 18 states fully conform. California, New York, New Jersey, Massachusetts, Connecticut, Pennsylvania (corporate), and many others require depreciation modifications. Texas, Florida, Tennessee, Nevada, Washington, Wyoming have no state income tax that affects cost seg. Check our state-specific pages for conformity status.

California's IRC conformity date is January 1, 2025, which excludes OBBBA. California uses pre-1981 depreciation rules for the federal-state difference, meaning the federal bonus depreciation is added back at the state level and the property depreciates over a longer state-only schedule.

Section 481(a) is the catch-up adjustment when changing accounting methods. For a look-back cost seg study, the 481(a) adjustment equals the difference between depreciation taken under the old method and what would have been allowed under the new (post-cost-seg) method. A negative (favorable) adjustment is taken entirely in the year of change.

No. The look-back is handled via Form 3115 (Designated Change Number 7 under Rev. Proc. 2022-14) filed with the current-year return, plus a duplicate filed to Ogden, Utah. The Section 481(a) catch-up adjustment flows entirely in the current year. No amended returns are required.

We track state conformity to OBBBA on our State Conformity Tracker page, updated as state legislatures adopt or decouple. Bloomberg Tax and the Council on State Taxation (COST) also publish authoritative conformity maps. State pages on this site cover federal-to-state interaction for each of the 50 states.