
M&A due diligence consulting and tax structuring for buyers and sellers
Thinking of buying or selling a business? M&A due diligence consulting from a CPA who models the tax structure before you sign, not after the deal closes.
Fill out the form and one of our experienced CPAs will get back to you shortly.

Cost segregation studies are a powerful tool for real estate investors, allowing them to accelerate depreciation on certain components of a property and reduce taxable income. But one common question that arises is: How far back can you perform a cost segregation study? The short answer is that you can apply a cost segregation study retroactively, sometimes going as far back as 15 years after the property acquisition.
12+
Years Serving NYC
50
States Covered
5★
Rated on Yelp
150,000+
Returns Filed
Open
Evenings & Weekends
Before diving into the details of retroactive studies, it’s essential to understand what a cost segregation study is. This study breaks down the costs of a property into different asset categories, identifying parts of the property that can be depreciated more quickly than the building itself. For example, personal property like carpeting, lighting, or certain fixtures may qualify for accelerated depreciation, which can offer significant tax savings.
The key to retroactively applying a cost segregation study lies in IRS Form 3115, “Application for Change in Accounting Method.” This form allows property owners to adjust their depreciation schedule and recapture missed deductions from previous years. When you file Form 3115, you essentially request permission from the IRS to change your depreciation method to one that reflects the findings of the cost segregation study.
Under certain conditions, this retroactive application can extend back as far as 15 years after the date the property was acquired. This means that if you’ve owned a property for several years without taking full advantage of accelerated depreciation, you can still reap the benefits of a cost segregation study by adjusting past tax returns.
There are several reasons you might want to consider applying a cost segregation study retroactively:
In conclusion, you can conduct a cost segregation study up to 15 years after acquiring a property using IRS Form 3115, potentially unlocking significant tax benefits and giving you a second chance to maximize your property’s depreciation. If you’re considering this route, working with a tax professional familiar with cost segregation and IRS guidelines is essential to ensure compliance and maximize savings.
No cost to start
Fifteen minutes with a CPA who handles this every week. We will walk you through your options — no sales pitch, no obligation.
“George has prepared and maintained the corporate accounting and provided consultant services for my company for a number of years. He has always done an outstanding, professional and courteous job. I feel that his rates are very fair and he provides a great value for the cost.”
“Excellent service and very professional. George and his team have been handling my business taxes for years and I couldn't be happier with the results. They are always available to answer questions and provide expert advice.”
“I've been working with Dimov CPA for both personal and business taxes. Their attention to detail and knowledge of tax law has saved me thousands. Highly recommend to anyone looking for a reliable CPA in NYC.”
Keep reading

Thinking of buying or selling a business? M&A due diligence consulting from a CPA who models the tax structure before you sign, not after the deal closes.

A New York CPA tracks New York tax law changes as they happen. MCTMT rates, 2026 brackets, SALT and PTET, and the remote worker rule that still applies.

A New York CPA on how to offset W2 income with real estate. Short term rentals, material participation, cost segregation, and the traps that undo it all.
Ready when you are
A CPA will review your situation and give you a straight answer. No commitment, no jargon.