This case study examines how a high-income W-2 professional with $1.1M in annual salary and three long-term rental properties reclassified one property as a short-term rental, corrected 9 years of missed depreciation through Form 3115, and implemented cost segregation to reduce annual tax liability from $385,000 to approximately $314,000 - a reduction of $71,000 annually.

The Client Situation

Our client was a corporate executive earning $1.1M in W-2 salary with three residential properties acquired 9-12 years prior, held as long-term rentals. The properties generated approximately $65,000 in combined annual rental income.

The client's tax preparer had been using gross depreciation of approximately 3.5% annually (approximately $21,000) on the combined properties, which significantly understated proper MACRS depreciation. Additionally, one property (a beach home) had substantial market demand for short-term vacation rentals, but had been held exclusively for long-term lease.

Strategy 1: Long-Term to Short-Term Rental Conversion

We recommended converting one of the three properties (the beach home, $380,000 basis) from long-term rental to short-term rental (Airbnb-style) operation. This conversion served multiple purposes: (1) Increased cash flow potential (STRs typically generate higher revenue per unit-day than LTRs); (2) Changed property classification from residential property (27.5-year MACRS under IRC Section 168(c)) to non-residential property (39-year MACRS under IRC Section 168(e)); (3) Enabled cost segregation analysis with more aggressive personal property allocation typical for commercial property.

Under IRC Section 280A and Treasury Regulation Section 1.280A-1, the property classification is determined by actual use during the tax year. By renting the beach home on 120+ days annually as a short-term rental (versus continuous long-term lease), the property met the genuine STR business classification.

Strategy 2: Form 3115 Depreciation Correction Across All Three Properties

We filed Form 3115 to correct the prior incorrect depreciation method. The client's prior preparer had not properly allocated basis between land and building, had not depreciated capital improvements, and had used a simplified percentage rather than MACRS tables.

Proper analysis of the three properties:

• Property A (LTR, remained LTR): $420,000 basis, allocated 82% building ($344,400) / 18% land. Proper 27.5-year MACRS: $12,516 annually (vs. prior $14,700 oversimplified estimate - actually the prior method overstated).
• Property B (LTR, remained LTR): $360,000 basis, allocated 80% building ($288,000) / 20% land. Proper 27.5-year MACRS: $10,472 annually (vs. prior $12,600).
• Property C (converted to STR): $380,000 basis, allocated 85% building ($323,000) / 15% land. Now 39-year MACRS: $8,282 annually as building (vs. prior 27.5-year calculation giving incorrect rate). Plus: Personal property segregation ($57,000 allocated to furniture/fixtures) eligible for 7-year MACRS = $8,143 annually.

Year 1 proper depreciation: $12,516 + $10,472 + $8,282 + $8,143 = $39,413.

Prior 9-year cumulative depreciation (understated): Approximately $189,000. Proper 9-year cumulative: Approximately $354,717. Cumulative understatement: $165,717.

Under IRC Section 481(c), this catch-up was spread over four years = approximately $41,429 annual adjustment. Tax benefit at 35% rate: $14,500 annually.

Strategy 3: Bonus Depreciation on STR Personal Property

The $57,000 in personal property components identified through cost segregation on Property C qualified for 100% bonus depreciation under IRC Section 168(k) in the year of the Form 3115 filing.

This created an immediate Year 1 deduction of $57,000 (bonus) on top of the regular MACRS depreciation, generating additional $19,950 in tax savings at the 35% marginal rate.

Practical Implementation: The Three-Year Tax Impact

Year 1 (Form 3115 Filing Year and STR Conversion): W-2 income $1,100,000. Bonus depreciation (Property C personal property) $57,000. Form 3115 catch-up adjustment $41,429. Regular depreciation on all properties $39,413. Total depreciation-related deductions: $137,842. Taxable income after deductions: $962,158. Federal tax: approximately $336,000 (vs. approximately $385,000 prior). Year 1 savings: $49,000.

Years 2-4 (Post-bonus depreciation, during catch-up spread): Annual catch-up adjustment $41,429 + annual depreciation $39,413 = approximately $80,842 annual deduction. Tax savings: approximately $28,295 annually, or $84,885 over three years (Years 2-4).

Year 5+: Catch-up adjustments end; regular depreciation continues at approximately $39,413 annually, saving $13,795 annually.

Total four-year savings (Years 1-4): Approximately $49,000 + $84,885 = $133,885. Average annual savings: Approximately $33,000.

Key IRC Provisions

• IRC Section 446(e): Accounting method change
• IRC Section 481(c): Catch-up adjustment spread provision
• IRC Section 168(c): Residential property recovery period (27.5 years)
• IRC Section 168(e): Non-residential property recovery period (39 years)
• IRC Section 168(k): Bonus depreciation (100% through 2026)
• IRC Section 280A: Short-term rental property classification
• Treasury Regulation Section 1.280A-1: Determination of dwelling unit use