Overview

• Participants age 50 and older with prior‑year FICA wages above $145,000 (indexed) must make catch‑up contributions on an after‑tax Roth basis in 401(k), 403(b) and governmental 457(b) plans.
• The mandate takes effect on January 1, 2026, with the IRS allowing reasonable, good‑faith administration during 2026 and requiring full regulatory compliance by January 1, 2027.
• Workers in plans without a Roth option cannot make catch‑up contributions if they exceed the wage threshold, prompting many employers to add Roth features.
• Final rules permit plan design choices such as a deemed Roth election for affected earners and optional aggregation of wages across related employers, plus defined fixes for errors via Form W‑2 correction or in‑plan Roth rollover.
• An optional higher “super” catch‑up for ages 60–63 remains available at 150% of the standard limit ($11,250 for 2025), and most 401(k)/403(b) plans must adopt required SECURE 2.0 amendments by December 31, 2026.