Cost segregation is an engineering and tax study that identifies and reclassifies components of a real property asset from the 39-year depreciation schedule (used for commercial buildings) or 27.5-year schedule (used for residential rental property) into shorter-lived categories: 5-year, 7-year, or 15-year property. The result is larger depreciation deductions in the early years of ownership, which reduces taxable income significantly in those years.
How Does Cost Segregation Work?
A qualified engineer or CPA performs a cost segregation study by reviewing construction documents, blueprints, and invoices to identify which building components qualify for accelerated depreciation. Typical components reclassified into shorter-lived categories:
- 5-year property: carpet, certain fixtures, decorative lighting, appliances
- 7-year property: office furniture, certain equipment attached to the building
- 15-year property: parking lots, landscaping, driveways, site preparation costs, certain land improvements
The building structure itself (foundation, walls, roof) remains on the 39-year or 27.5-year schedule.
Why Cost Segregation Matters
- Tax Savings: The primary benefit of cost segregation is the ability to accelerate depreciation, which leads to immediate tax deductions. This is particularly useful for businesses that own commercial or rental properties, as it helps reduce their tax liability in the short term.
- Cash Flow Benefits: By increasing depreciation deductions in the early years of ownership, businesses can significantly improve cash flow. The savings from reduced taxes can be reinvested into the business, used to pay down debt, or used for capital expenditures.
- Increased Property Value: Although the property’s book value may be reduced due to the accelerated depreciation, the improved cash flow can enhance the overall financial position of the business. This can make it easier to secure financing or reinvest in other opportunities.
- Compliance with Tax Laws: Cost segregation studies help ensure that businesses comply with IRS rules and regulations regarding depreciation. This can protect property owners in the event of an audit by providing clear documentation of how assets have been categorized and depreciated.
Cost Segregation Tax Savings Example
A commercial property owner purchases a $2,000,000 building. Without cost segregation, the annual depreciation deduction is $2,000,000 / 39 years = $51,282 per year.
After a cost segregation study, $600,000 of the building is reclassified to 5-year property. Combined with 100% bonus depreciation under the One Big Beautiful Bill Act (permanent as of 2025), the owner can deduct the full $600,000 in Year 1 instead of over 39 years. On a $600,000 accelerated deduction at a 37% effective rate: estimated first-year tax savings of $222,000.
Use our real estate calculator for better understating.
Challenges
- Upfront Costs: Conducting a cost segregation study requires the help of professionals, such as tax experts or engineers, which can involve substantial upfront costs. However, the long-term tax savings often outweigh these initial expenses.
- IRS Scrutiny: While cost segregation is a legitimate tax strategy, it must be done in compliance with IRS guidelines. A poorly executed cost segregation study could result in penalties, interest, or an audit. Therefore, it is crucial to work with experienced professionals to ensure that the study is thorough and meets all regulatory requirements.
- Complexity of Process: Identifying and classifying assets correctly can be complex, especially in large properties with many components. Property owners must ensure that their cost segregation study accurately reflects all eligible assets and complies with tax regulations.
Best Practices
- Work with a Professional: Given the complexity of cost segregation, it’s essential to work with professionals, such as tax advisors, engineers, or accountants, who specialize in this area. They can help ensure that the study is thorough and compliant with IRS rules.
- Timing: The best time to conduct a cost segregation study is when a property is acquired, but it can also be done on existing properties to catch up on depreciation missed in previous years.
- Documentation: Keep detailed records of the cost segregation study, including the methodology used to classify assets and the depreciation schedules applied. This documentation will be crucial in the event of an IRS audit.
Who Qualifies for Cost Segregation?
Property owners who have purchased, constructed, or renovated commercial or residential rental real estate. Cost segregation studies are typically cost-effective when the building value (excluding land) exceeds $500,000. However, studies on smaller properties (down to $200,000) can still be justified when bonus depreciation is available.
Most beneficial for: commercial real estate investors, hotel and hospitality owners, retail property owners, medical and dental office owners, industrial and warehouse facilities, and multi-family apartment owners.
How Much Does a Cost Segregation Study Cost?
A qualified cost segregation study typically costs $5,000 to $15,000 for a property in the $500,000 to $5,000,000 range. On a $1,000,000 property, a study costing $8,000 that generates $80,000 in accelerated first-year deductions — saving $29,600 in taxes at 37%, returns the study fee many times over in Year 1 alone.
Cost Segregation and the 2026 Bonus Depreciation Rules
The One Big Beautiful Bill Act (OBBBA), signed July 4, 2025, made 100% bonus depreciation permanent for qualified property placed in service from 2025 onwards. This dramatically increases the value of cost segregation studies because all reclassified personal property (5-year and 7-year assets) can now be fully deducted in the year placed in service. For a property placed in service in 2026, the combination of a cost segregation study and 100% bonus depreciation can generate a first-year deduction of 20-40% of the total building purchase price.