Roth vs Traditional 401(k): The Definitive Tax Bracket Analysis for 2026

With TCJA provisions sunsetting after 2025, the Roth vs Traditional 401(k) decision has never been more consequential. This analysis models a $23,500 contribution across every 2026 tax bracket using CBO-projected future rates. Topics include marginal vs effective rate analysis, breakeven tax rate calculation, when Roth wins vs when Traditional wins, the split contribution strategy, SECURE Act 2.0 mandatory Roth catch-up for $145K+ earners, state tax considerations, and RMD implications.