Cost Segregation Bonus Depreciation Calculator 2026
Cost segregation studies reclassify portions of commercial real estate from 27.5/39-year MACRS to 5/7/15-year schedules, eligible for bonus depreciation. Typical study accelerates $80K-$300K of depreciation into first 5 years. This tool computes savings.
How Cost Segregation Works
Engineering-based study identifies building components eligible for shorter depreciation lives: 5-year (carpet, removable equipment), 7-year (fixtures), 15-year (land improvements, parking). Typically 20-40% of building basis can be reclassified, capturing accelerated depreciation in years 1-15 vs straight 27.5/39-year schedule.
Bonus Depreciation Phase-Out
2017 TCJA introduced 100% bonus depreciation for property placed in service 2018-2022, phasing down 20% per year afterward. 2026: 40%. 2027: 20%. 2028: 0%. OBBB 2025 did NOT extend bonus depreciation. Make placed-in-service decisions accordingly — accelerating into 2026 captures more than waiting.
When Cost Segregation Makes Sense
Study cost $5K-$15K typical, savings $25K-$500K+. Rule of thumb: breakeven on property > $500K basis. Highest ROI: commercial property (39-year MACRS), recently acquired or constructed (within 3 years), high-income owner (32%+ marginal rate). 1031 exchange recipients can do cost seg on replacement property — even better.
Source: IRS Cost Segregation Audit Techniques Guide, IRS Section 168(k) Bonus Depreciation, OBBB 2025. Last updated: May 2026.