A lot of owners think it is too late. They bought a rental five years ago and never did a cost segregation study. They figure that chance is gone.
It is not gone. The IRS has a form for exactly this. It is called Form 3115. It lets you go back, find the deductions you missed, and claim them all on this year's return. No amended returns. No going back through old years one by one.
The big idea: you do a cost segregation study now, figure out what you should have deducted in past years, and take that whole catch-up in one lump this year.
What Form 3115 actually does
Form 3115 is the Application for Change in Accounting Method. When you start depreciating parts of your building faster, the IRS sees that as a change in method. Form 3115 is how you make that change the right way.
The best part is the catch-up. The IRS calls it a Section 481(a) adjustment. It adds up all the extra depreciation you would have taken in past years and lets you claim it this year, in one number.
An example
Say you bought a $500,000 rental four years ago. You have been depreciating it slowly, over 27.5 years. A study now finds $120,000 of short-life parts that should have been written off much faster.
With Form 3115, you do not have to amend four old returns. You take the full catch-up, often most or all of that $120,000, as a deduction on this year's return. That can mean a large tax savings in a single year.
No amended returns. You claim every missed deduction in one catch-up, this year.
Why this beats amending old returns
- One return, not many. You file Form 3115 with this year's return instead of redoing several past years.
- No 3-year limit. Amended returns usually only reach back three years. The catch-up can pull in deductions from further back.
- It is automatic. This kind of change is on the IRS list of automatic changes, so you do not need special permission first.
Does my property still qualify?
Usually yes. The catch-up works on rentals and commercial buildings you have owned for a year or more. It also works on property you got through a 1031 exchange, an inheritance, or a gift, though the basis math takes a little more care. We handle that for you.
How we make it simple
Every study we deliver includes the Form 3115 prep when a catch-up applies. We do the engineering study, calculate the catch-up amount, and prepare the form so your tax preparer can file it with your return. It is built in, not an add-on. See what is included.
Next step: See your savings range in seconds for a property you already own, or read what is cost segregation? for the basics.
This guide explains general tax ideas in plain words. It is not tax advice for your situation. Form 3115 and the Section 481(a) catch-up have specific rules and timing. Your study and tax positions are reviewed by a licensed tax professional, and the form is filed by your preparer. Always confirm the plan with your own advisor.