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When Should You Do a Cost Segregation Study?

Dec 2024 1 min read

Last reviewed: 2026-02-26

Quick Summary

When Should You Do a Cost Segregation Study? Timing is everything when it comes to tax strategy.

Tax law changes over time. RentalWriteOff provides bonus depreciation applicability analysis in every report.

Timing is one of the most important cost segregation decisions. In most cases, earlier execution simplifies filing, but late studies can still create value.

Best-case timing: first filing year

The cleanest workflow is to complete the study for the same tax year the property is placed in service. This gives your CPA the classification package before return preparation is finalized.

Late study timing: still possible

If the property has already been depreciated under 27.5-year treatment, a late study may still support a catch-up adjustment. CPAs often evaluate Form 3115 when appropriate for method-change treatment.

What to gather before you start

  • Property address and placed-in-service date
  • Building cost basis support
  • Property photos or listing links
  • Optional closing package or appraisal documentation

CPA workflow note

RentalWriteOff provides the supporting study and bonus depreciation applicability analysis. Form 3115 support is available as an add-on when needed.

For a firm-ready intake and delivery process, see our CPA platform page.