Catching up missed depreciation without amending

What is it?

When depreciation has been under-claimed for years — a building depreciated over too long a life, an asset never set up correctly, or improvements that were never broken out — the tax law generally treats a consistent depreciation method as an accounting method. Correcting it is a change of method, and a change of method is made prospectively with a single catch-up adjustment rather than by rewriting the past.

The vehicle for the correction is an automatic accounting-method change filed on Form 3115. The form computes a one-time adjustment equal to the difference between the depreciation you did take and the depreciation you were entitled to take. That entire cumulative shortfall is picked up in the current year, so you do not have to amend each affected prior return.

This is especially valuable after a cost-segregation study performed on a building you have owned for several years. The study reclassifies portions of the building into shorter-lived components that should have been depreciating faster all along. The method change lets you claim the accumulated difference in the current year, capturing years of missed depreciation at once.

The catch-up adjustment can work in the taxpayer's favor as a deduction when depreciation was understated. Getting the mechanics right — that this is truly a method change and not simply an error — is what keeps the correction on the automatic-change path rather than forcing amended returns.

Who does it apply to?

Owners of buildings or equipment who have under-depreciated assets over two or more prior years because of a wrong life, class, or method.

Taxpayers who commission a cost-segregation study on a property held for several years and want to capture the accumulated difference now.

Businesses that never properly set up depreciation on assets placed in service in earlier years and have used that treatment consistently.

Who does it not work for?

• Errors that are not method changes — a one-time math or posting mistake is corrected by amending the affected return, not by a Form 3115 method change.
• Situations where the law actually requires amended returns rather than permitting a method change, so the automatic-change path is unavailable.
• Taxpayers who never placed the asset in service, since there is no depreciation to catch up on an asset that was not yet in use.
• Changes that fall outside the automatic-consent procedures and would require advance consent the taxpayer has not obtained.

What does the IRS look at?

• Whether the item is genuinely a change in accounting method — a consistent treatment over more than one year — rather than an isolated error.
• Whether the catch-up adjustment was computed correctly as the cumulative difference between depreciation taken and depreciation allowable.
• Whether the change qualifies under the automatic-consent procedures or instead required advance consent.
• Whether any underlying reclassification, such as a cost-segregation study, is supported by an adequate engineering and cost analysis.
• Whether the Form 3115 was filed for the correct year and with the return as the procedures require.

What does it cost to fund, and when does the window close?

There is no capital outlay — this is a procedure-driven filing, not an investment. The catch-up adjustment typically produces a current deduction rather than a cash cost, so the expense is professional time rather than money put at risk.

The work is detailed and best prepared by a CPA, often alongside a cost-segregation engineer where a building is involved. The Form 3115 is filed with the return for the year of change, so the analysis should be underway well before the return deadline rather than at the last moment.

Related strategies

• §168Accelerating depreciation on buildingsCapital outlay
• §168Immediate expensing of equipmentCapital outlay
• §446Which year income and deductions land inNo outlay

Common questions

How is this different from amending my old returns?

An amended return corrects a specific error on one specific past return. A change in accounting method on Form 3115 addresses a treatment applied consistently across more than one year and gathers the entire cumulative difference into a single adjustment in the year of change. Because that catch-up runs through the current return, the earlier years are not reopened one at a time.

Can I use Form 3115 after a cost-segregation study?

Yes, and it is one of the most common uses of the form. When an engineer's study reclassifies parts of a building you have owned for years into shorter-lived components, those components should have been depreciating faster from the start. The method change claims the accumulated difference on the current return instead of amending every year since the purchase. The study itself has to be backed by an adequate engineering and cost analysis.

Is a simple mistake a method change?

No. A one-time math error or a posting mistake is corrected by amending the affected return, because a change in accounting method requires a treatment applied consistently across more than one year. Filing Form 3115 for an isolated error puts the whole adjustment in question, and amending returns where the law requires a method change is generally not permitted. A CPA should settle which of the two routes applies before either is filed.

Mena Hemaia, CPA, CIA

Chief Executive Officer, Accountack — West Palm Beach, Florida

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