Cost segregation calculator: separate the deduction from the tax result.

Choose a bonus rate from the facts, not just the year

The restored 100% federal bonus allowance generally applies to eligible property acquired and placed in service after January 19, 2025. Acquisition rules, including written binding contracts, can change the answer. Used-property eligibility, elections, and exclusions still matter.

For qualifying property under the earlier phase-down rules, ordinary rates include 60% for 2024, 40% for 2025, and 20% for 2026. Special categories and transitional elections can differ. This screen does not determine which rule applies to your assets.

Do not select 100% simply because a cost segregation study is completed in 2026. The original acquisition and service dates are relevant when reviewing existing property.

• Review bonus depreciation eligibility and timing
• When an existing property may require Form 3115

What the illustrative inputs mean

A $500,000 purchase basis containing $100,000 of land leaves $400,000 before further basis adjustments. An assumed 25% short-life allocation produces $100,000 of modeled short-life basis. At a chosen 100% bonus rate, the bonus component is $100,000.

At an assumed constant 37% federal marginal rate, the tax effect would be $37,000 only if that entire component is usable at that rate. This is not $37,000 of incremental savings over the depreciation otherwise available, and it is not a projected refund.

The 25% input is hypothetical. We do not treat a property category as proof of the engineering allocation. The calculator omits ordinary depreciation on remaining basis and does not spread remaining deductions evenly across an invented five-year schedule.

What must be reviewed before acting

A large deduction may be suspended or have a different tax value than the selected rate suggests. Comparing a study with doing nothing requires modeling the baseline depreciation as well as these omitted factors.

• Supported land and building basis, closing adjustments, improvements, and the property's actual placed-in-service history.
• An asset-level study and the eligibility of reclassified assets for the chosen treatment.
• Basis, at-risk, passive-activity, excess-business-loss, and other applicable limits on using deductions.
• Prior depreciation and the correct procedure for any correction or method change.
• Study and implementation fees, state conformity, future disposition and recapture, and the time value of accelerated deductions.

• Cost segregation planning and study fit
• Separate STR participation and loss-use rules

Bring the records, not just the calculator result

Taxstra can discuss study coordination and CPA implementation as separately defined responsibilities. Bring closing statements, depreciation schedules, ownership details, and the next property decision to the engagement.

A provider quote and an engineering conclusion are different from a screening input. We define the tax work, reporting responsibilities, and fees before proceeding.

• Discuss cost segregation CPA coordination
• Review the rest of your real-estate tax situation

Common questions

Sources and further reading

• IRS Topic 704: depreciation and the acquisition/service requirement
• IRS Publication 946: basis, bonus, elections, and methods
• IRS Notice 2026-11: additional first-year depreciation guidance
• IRS Publication 925: passive activity and at-risk limits

Discuss your next decision with Taxstra

Book a free 30-minute initial consultation. We will discuss your situation, whether we are a fit, and the scope and fees for the next step. The initial call is not a completed tax plan or a review opinion.

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