C Corp Tax 2025

Corporate Tax Planning 2025

A strategic roadmap to the "One Big Beautiful Bill Act" (OBBBA): Leveraging permanent full expensing while navigating the Corporate AMT minefield.

Executive Summary

The 2025 tax year represents a seismic shift. The One Big Beautiful Bill Act (OBBBA) has permanently restored 100% Bonus Depreciation and immediate R&E Expensing (Section 174A), creating massive liquidity opportunities.

However, these benefits come with a catch: the Corporate Alternative Minimum Tax (CAMT). For large entities, aggressive tax deductions that lower "Regular Tax" do not reduce "Financial Statement Income," potentially triggering a 15% minimum tax that claws back the savings.

The Stimulus

100% Expensing: Permanent Bonus Depreciation and Domestic R&E Expensing. Interest limits revert to EBITDA-based ATI.

The Floor

CAMT (15%): Large corps (>$1B AFSI) must pay the greater of Regular Tax (21%) or 15% of Book Income.

The Trap

State Decoupling: States like CA and NY may not conform to federal expensing, requiring separate books and tax add-backs.

Corporate AMT (CAMT)

The "Book-Tax" Trap

Warning: Taking huge tax deductions (Bonus Dep/R&E) lowers your Regular Tax but leaves Book Income high. This widens the gap, making it more likely you will owe CAMT.

Who is an "Applicable Corporation"?

  • General Rule: Average Annual Adjusted Financial Statement Income (AFSI) > $1 Billion (3-year avg).
  • Foreign Parent: Group AFSI > $1 Billion AND U.S. Member AFSI > $100 Million.
  • Safe Harbor: Interim Simplified Method (2025): Thresholds reduced to $800M / $80M using simpler math to prove non-applicability.

Restored Expensing (Bonus & R&E)

The "Tax on Innovation" is over. Domestic R&D is fully deductible again.

100% Bonus Depreciation

  • Rate: Permanently restored to 100%.
  • Straddle Trap: Assets acquired Jan 1 - Jan 19, 2025 get only 40%. Must be acquired after Jan 19th.
  • Eligible: Machinery, Equipment, Vehicles, QIP (Interior Improvements).

R&E Expensing (Sec 174A)

  • Domestic: Immediate 100% deduction (Effective 2025).
  • Foreign: Must still capitalize over 15 years.
  • Small Biz Relief: <$31M Gross Receipts? You can elect retroactive expensing for 2022-2024 via amended returns.

Interest Deduction (Sec 163(j))

Return to EBITDA

Leverage is unlocked again.

Period Base Impact
2022 - 2024 (TCJA) EBIT Strict limit. Depreciation hurts cap.
2025+ (OBBBA) EBITDA Add back Dep/Amort. ~50% more debt capacity.

State Divergence Matrix

States cannot afford the revenue loss from federal expensing. Expect massive "decoupling."

Rolling Conformity (e.g., NY, IL)

Usually adopt federal changes automatically. Watch out: Legislatures will likely pass bills to force add-backs of Bonus Depreciation.

Static Conformity (e.g., CA, TX)

Stuck in the past. CA typically does not conform to Bonus Depreciation or new R&E rules without specific action.

Interactive: CAMT Analyzer

Estimate your 2025 tax liability. See how aggressive expensing lowers Regular Tax but might trigger CAMT.

Financials (Millions $)

Must be >$1,000M to trigger generally.

100% Bonus + R&E Expensing amounts.

Liability Calculation

Regular Tax (21%)
Base: $0
$0
Tentative Min Tax (15%)
Base: AFSI
$0
Total Tax Liability
Greater of Reg or CAMT
$0