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100% Bonus vs 40% Election Under Section 168(k)(10)

By Zawwad Ul Sami, Founder, WeCostSegPublished: 2026-05-14Last updated: 2026-05-14

Elect 40% bonus depreciation under Section 168(k)(10) when 100% would create a net operating loss the taxpayer would prefer to use across multiple years rather than carry forward. Elect 40% when state-level conformity is more favorable at the partial rate. Otherwise take 100% bonus. The election is class-by-class and irrevocable for the year.

The election under Section 168(k)(10)

OBBBA added Section 168(k)(10) permitting a taxpayer to elect 40% bonus depreciation (60% for long-production-period property and certain aircraft) for the first tax year ending after January 19, 2025. The election is class-by-class. A taxpayer can elect 40% on 5-year property while taking 100% on 15-year property.

The election is made via statement attached to the return. Irrevocable for the year. IRS Notice 2026-11 covers the mechanics.

When 40% election wins

If 100% bonus would create a net operating loss larger than the taxpayer can absorb, the 40% election preserves NOL absorption capacity. The 60% of basis not deducted in year one depreciates on regular MACRS in years 2-6 (5-year property) or years 2-16 (15-year land improvements).

If state conformity is decoupled at 100% but accepted at lower rates, the 40% election captures more state-level benefit. California's decoupling is the most common case where this analysis matters.

When 100% wins

If the taxpayer can fully absorb the 100% bonus depreciation in year one (passive income, REPS, or STR loophole), 100% wins. Maximum first-year deduction at the highest marginal rate available.

If state conformity is uniform (rolling-conformity state), 100% wins because the state benefit matches the federal benefit. No state-level reason to limit the federal deduction.

Frequently asked questions

How does WeCostSeg coordinate with my CPA?
Every engagement follows the three-touch CPA Coordination Protocol. Preliminary analysis CC'd to your CPA on intake, draft report shared five business days before final delivery, and Form 3115 filing coordinated when a Section 481(a) adjustment applies.
Does OBBBA's 100% bonus apply to my acquisition?
100% applies to property under a binding contract on or after January 20, 2025 per Public Law 119-21. Property under a binding contract on or before January 19, 2025 stays on the legacy phase-down: 40% in 2025, 20% in 2026, 0% in 2027 and after.
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Yes. Every WeCostSeg engagement includes five years of written audit defense at no extra charge, aligned to the 13 Principal Elements of a Quality Cost Segregation Study under IRS Publication 5653 Chapter 4.
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About the author

Zawwad Ul Sami, Founder

Zawwad Ul Sami is the founder of WeCostSeg, a founder-led cost segregation firm serving real estate investors across the US. He focuses on strategy, pricing, and the firm's overall direction.