Cost Segregation Strategies for Real Estate Owners and Small Business

If you own commercial real estate, rental property, or a building used in your business, you are likely depreciating it over 27.5 or 39 years — the standard IRS recovery periods for residential and nonresidential real property. But a significant portion of every building can be depreciated much faster — over 5, 7, or 15 years — if properly identified and classified.

That is the core of cost segregation: an engineering-based tax strategy that accelerates depreciation deductions, defers tax liability, and improves cash flow. For the right property, the first-year benefit can reach six figures or more.

When you purchase or construct a building, the IRS requires you to recover the cost over its useful life. For a commercial building, that is 39 years. For residential rental property, it is 27.5 years. That means a $1 million building generates roughly $25,000–$36,000 in annual depreciation deductions under the standard approach.

But buildings are not monolithic. They contain components with much shorter useful lives:

• 5-year property: Carpeting, certain fixtures, specialized equipment, land improvements in some cases
• 7-year property: Office furniture, certain equipment, some interior improvements
• 15-year property: Land improvements (parking lots, sidewalks, landscaping, fencing), certain exterior improvements

A cost segregation study identifies and reclassifies these components from 27.5- or 39-year property into shorter-lived categories — dramatically accelerating the depreciation deductions available in the early years of ownership.

Cost segregation becomes even more powerful when combined with bonus depreciation. Under current law (as extended and modified by the Tax Cuts and Jobs Act), qualified property with a recovery period of 20 years or less is eligible for bonus depreciation — meaning the entire cost can be deducted in the year placed in service, rather than over its recovery period.

The bonus depreciation percentage has been phasing down:

• 2023: 80%
• 2024: 60%
• 2025: 40%
• 2026: 20%
• 2027 and beyond: 0% (under current law)

This phase-down makes timing critical. A cost segregation study completed today captures a higher bonus depreciation percentage than one completed in 2027. For property placed in service in prior years, a catch-up study can still generate significant deductions — often in a single year through a Form 3115 accounting method change.

A cost segregation study is an engineering and tax analysis performed by qualified professionals. The process typically includes:

1. Site visit or document review: The engineer reviews construction documents, blueprints, cost records, and (ideally) inspects the property
2. Component identification: Each building component is identified and assigned to the appropriate asset class
3. Cost allocation: The total cost basis is allocated among the identified components
4. Report preparation: A detailed, audit-ready report is prepared documenting the methodology, findings, and depreciation schedules
5. Tax return integration: The reclassified assets are reported on your tax return with updated depreciation schedules

The IRS expects cost segregation studies to be performed by qualified engineers or tax professionals with engineering expertise. A study prepared by someone without that background is unlikely to withstand scrutiny in an audit.

Cost segregation is most valuable for:

Real estate investors with commercial or residential rental properties — particularly those with a cost basis above $500,000. The larger the property, the greater the potential benefit.

Business owners who own their building — whether a medical office, retail location, restaurant, or industrial facility. If your business occupies the property, the depreciation deductions flow directly to your return.

Recent purchasers — the year of acquisition is the optimal time for a study, as you can capture the maximum benefit going forward. But catch-up studies for properties held for years are also highly effective.

High-income taxpayers — the value of accelerated depreciation is greatest when you are in a high marginal tax bracket. A $200,000 deduction is worth $74,000 in tax savings at the 37% rate.

Real estate professionals — taxpayers who qualify as real estate professionals under IRC Section 469 can use rental losses (including depreciation) to offset ordinary income without limitation, making cost segregation especially powerful.

One of the most common misconceptions about cost segregation is that it must be done in the year of purchase. That is not true. The IRS allows taxpayers to perform a catch-up cost segregation study on property placed in service in prior years and claim the cumulative missed depreciation in a single year — without amending prior returns.

This is accomplished through a Form 3115 accounting method change. The Section 481(a) adjustment represents all the depreciation you could have taken in prior years but did not. That entire amount is deductible in the year of change.

For a property purchased five years ago, this can mean a very large deduction in the current year — effectively compressing years of missed depreciation into a single filing.

One important caveat: depreciation deductions from rental properties are generally treated as passive losses, which can only offset passive income — not wages, business income, or investment income. If you have no other passive income, the losses may be suspended and carried forward.

There are two primary exceptions:

The $25,000 Allowance: Taxpayers with modified AGI below $100,000 who actively participate in rental activities can deduct up to $25,000 of rental losses against ordinary income. This phases out between $100,000 and $150,000 of AGI.

Real Estate Professional Status: Taxpayers who spend more than 750 hours per year in real property trades or businesses — and for whom real estate constitutes more than half of their total working hours — can treat rental losses as non-passive. This allows unlimited deductions against ordinary income, making cost segregation dramatically more valuable.

If you are considering a cost segregation study and are not sure whether passive activity rules will limit your benefit, a CPA can model the outcome before you invest in the study.

The cost of a cost segregation study varies based on property size and complexity — typically ranging from $5,000 to $15,000 for most commercial properties. The tax savings almost always dwarf the cost.

A simple example:

• Property: $2 million commercial building
• Reclassified to shorter-lived property: $400,000 (20% of cost basis)
• Bonus depreciation (60% in 2024): $240,000 additional first-year deduction
• Tax savings at 37% rate: ~$88,800
• Study cost: ~$8,000
• Net first-year benefit: ~$80,800

That is a return on investment of over 1,000% — in the first year alone.

Cost segregation works well in combination with other tax strategies:

• Opportunity Zone investments: Defer and potentially reduce capital gains by reinvesting in Qualified Opportunity Zones
• 1031 exchanges: Defer capital gains on property sales by reinvesting in like-kind property
• Qualified Improvement Property (QIP): Interior improvements to nonresidential buildings have a 15-year life and are eligible for bonus depreciation
• Section 179: An alternative to bonus depreciation for certain property, with different limitations and phase-outs

The right combination depends on your specific situation, income level, and long-term investment strategy.

Not all CPAs have experience with cost segregation studies. The analysis requires engineering expertise, knowledge of IRS asset classification rules, and familiarity with the audit documentation standards the IRS expects.

At Autarky Tax and Accounting, we work with qualified engineers to deliver IRS-compliant cost segregation studies for commercial and residential investment properties throughout Arizona and nationwide. We handle the study, the Form 3115 filing if needed, and the integration with your tax return — so you capture every dollar of benefit available. Learn more about our cost segregation services.

Contact us to find out how much a cost segregation study could save you.

Download our comprehensive PDF overview of how cost segregation works, what qualifies, and what to expect from the study process.

Download the ATG Cost Segregation Guide (PDF)