Form 3115 and Section 481(a) Catch-Up Depreciation
Answers to five connected questions about form 3115 and section 481(a) catch-up depreciation. Review IRS sources, practical facts, records and filing responsibilities.
The decision this guide resolves
An accounting-method change is a procedural filing, not simply a study attachment. Eligibility, designated change, timing, statements and duplicate-copy requirements must be checked.
A practical fact pattern
A completed engineering report arrives near the return deadline. The preparer still needs time to reconcile asset schedules, compute the adjustment and prepare the proper application.
Records to gather before deciding
- Complete filed depreciation history
- Study reconciliation and corrected method schedules
- Return deadline, extensions and prior method changes
Frequently Asked Questions
What does Form 3115 do for cost segregation?
It requests consent to change an accounting method when required and applicable. For eligible depreciation changes, the process can incorporate a cumulative Section 481(a) adjustment. The filer must identify the correct change, eligibility and procedural requirements rather than treating every study as an automatic approval.
What is a Section 481(a) adjustment?
It accounts for amounts needed to prevent duplication or omission when changing methods. In depreciation work, it compares the relevant cumulative treatment under the old and new methods. The study’s reclassified basis is not itself the adjustment; prior depreciation and year-of-change treatment must be reconciled.
Is a negative adjustment always deducted all at once?
A negative adjustment is generally taken in the year of change under applicable procedures, while positive adjustments generally have a different period and exceptions. First establish eligibility and the correct calculation. Other loss limitations may defer use even when the method-change rules recognize the deduction that year.
Does Form 3115 require an IRS user fee?
Eligible automatic-consent changes generally do not require a user fee, while nonautomatic applications generally do. Professional preparation fees are separate. Confirm the current change category and exceptions; a vendor saying the form is free does not establish the entire project cost or eligibility.
When is the Form 3115 duplicate copy due?
Automatic-change procedures generally require attachment to the timely filed original return, including extensions, plus a duplicate copy under the current instructions and procedure. Timing and delivery rules differ by filing route. Confirm the current authorized submission method and deadline rather than using an old mailing address or a study delivery date.
How to turn the answers into a return decision
Write down the property owner, affected tax year, the factual test being used and the evidence supporting it. Reconcile the amount on the study or workpaper with the return schedule, identify any limitation and assign the filing task to a named preparer. If a fact is missing, resolve it before treating the estimated deduction as usable.
Continue the planning sequence
Reviewed sources and scope
Reviewed November 8, 2026 by AE Tax Advisors. This is a federal planning resource; the facts, tax year, elections and state rules control the actual return. IRS publications explain rules but do not replace applicable law. The cost segregation audit guide is nonbinding examiner guidance and predates later bonus-depreciation changes.
Bring the facts to a scoped review
A study estimates asset classifications; a tax review determines eligible and currently usable deductions. Ask who reconciles basis, prepares any Form 3115 or amended return, and implements the final schedules. No tax saving or investment outcome is guaranteed.
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Discuss your priorities, upcoming decisions and whether a study or advisory engagement fits. Detailed analysis, implementation or filing work follows an agreed written scope.