Cost Segregation for Rental Property: How It Works and What It Saves

Depreciation is the quiet engine behind real estate tax efficiency, and cost segregation is how serious investors turn that engine up. Instead of writing off a building slowly over decades, a cost segregation study reclassifies parts of the property into much shorter tax lives, pulling large deductions into the early years of ownership.

This guide explains what a study does, roughly how much it can save, and when it is worth paying for.

How normal depreciation works

When you buy a rental, you cannot deduct the purchase price all at once. You depreciate the building portion, not the land, over 27.5 years for residential property or 39 years for commercial. On a 400,000 dollar residential rental with 20 percent land, that is a 320,000 dollar building basis and roughly 11,600 dollars of deductions each year. You can estimate this for any property with the depreciation calculator.

What cost segregation changes

A cost segregation study, usually performed by an engineering firm, breaks the building into components and assigns each to its correct tax life:

A typical study reclassifies 20 to 40 percent of the building basis into those 5 and 15-year buckets. Because that short-life property is eligible for bonus depreciation, you can deduct much of it immediately rather than spreading it out. The cost segregation calculator estimates the first-year benefit for your numbers.

Bonus depreciation makes it bigger

Bonus depreciation lets you deduct a large percentage of qualifying short-life property in the year it is placed in service. The 2025 tax law restored 100 percent bonus depreciation, after it had phased down to 60 percent in 2024. That means the entire reclassified amount from a study can often be deducted in year one. See the bonus depreciation calculator for the percentage that applies to a given year.

Is a study worth it?

A study usually makes sense when the building basis is above roughly 150,000 to 300,000 dollars and the first-year tax savings clear the study cost several times over. Engineered studies commonly run 5,000 to 15,000 dollars, and automated studies can be far less. The payback often lands under a year for a solid rental.

The catch: depreciation recapture

Accelerating depreciation does not create free money, it shifts the timing. When you sell, the depreciation you took is recaptured and taxed, up to 25 percent. You can defer that with a 1031 exchange into another property. Plan for recapture so a big year-one deduction does not become a surprise at sale.

Bottom line

Cost segregation is one of the highest-leverage tax moves available to rental investors, especially now that 100 percent bonus depreciation is back. Run your property through the investor tax tools to size the benefit, then confirm the specifics with a CPA and a qualified cost segregation provider.