IRC §174 R&D Capitalization State Conformity & Decoupling Matrix (2025/2026)

The Industry Bottleneck

Under TCJA amendments to IRC §174, domestic research and experimental (R&E) software engineering costs must be capitalized and amortized over 5 years (10% Year 1 mid-year convention). However, most generalist CPAs forget to adjust state taxable income in states that decouple from post-2021 IRC §174.

Technical Implementation & Workpaper Rules

• California (8.84% rate) and Georgia (5.39% rate) decouple from mandatory TCJA §174 amortization—permitting a 100% subtraction modification on the state return for current-year R&D spend.
• On a $4,000,000 domestic engineering payroll, federal Year 1 amortization is only $400,000 (+$3,200,000 M-1 addition after PY layer). Deducting that $3,200,000 on the CA Schedule R saves over $67,000 in immediate cash tax at a 24% CA apportionment factor.
• Under ASC 740, the $3,200,000 temporary difference creates a Federal Deferred Tax Asset ($672,000 @ 21%), while state deferreds must be adjusted for non-conforming states.