They bought a 6-unit multifamily in Austin in August 2025. Their CPA filed one form. They wrote off three hundred forty-two thousand dollars in year one — and every number traces back to an IRS citation.
The exact kind of acquisition that benefits most from the 2025 bonus depreciation restoration — recent placed-in-service date, residential rental, and a CPA willing to file Form 3115 if it had been older.
The building shell — walls, roof, structural — still depreciates over 27.5 years and gets no bonus. The 5- and 15-year components are what bonus depreciation actually accelerates. A real study identifies exactly which components qualify.
The bonus percentage doesn't change with when you file. It's locked in by when the property was placed in service. Properties acquired during the 2023-mid-2025 phase-down are stuck with a lower bonus % forever — but the deduction can still be captured through a lookback study.
Year-one math: 100% bonus on the $325,600 of reclassified short-life basis, plus first-year MACRS on the building shell. Total deduction lands on the Chens' 2025 return.
Cost seg only delivers if the study survives review. Unlevered's engine is built on the assumption that every number on the return will be defended — to a client, to a peer reviewer, or to an IRS examiner.
Each component reclassification points to the IRS Cost Seg Audit Techniques Guide, a revenue ruling, or controlling case law. No "trust us" line items. The workpaper is the audit trail.
Every study is engineer-certified before it lands on the CPA's queue. The CPA accepts, overrides, or escalates each reclassification. Nothing reaches the final return without CPA sign-off, and the audit log shows who decided what.
When a method change is required, the engine populates Form 3115 with the right DCN, §481(a) adjustment, and supporting schedules. Form 4562 workpaper is generated for every study. You review and file.
Each study ships with a 0-100 defensibility score and a band: 85+ (strong), 65-84 (defensible with documentation), <65 (escalate). Soft numbers don't sneak through.
Adjust the placed-in-service year and the depreciable basis. The estimator applies a typical residential reclassification ratio and the bonus % for that year. Useful for shaping a client conversation — not a substitute for a real study.
Every residential rental in your book of business placed in service after Jan 19, 2025 sits on 100% bonus eligibility. The ones placed in service earlier qualify for a lookback. Both flow through the same engine.
