Mandatory Roth Catch-Up for High Earners ($155,000 Rule)

Short answer: Under SECURE 2.0 Section 603 (final regulations published September 16, 2025, effective for taxable years beginning after December 31, 2026), if your 2026 FICA wages (W-2 Box 3) from the employer sponsoring your plan exceeded $155,000, your 2027 catch-up contributions must be Roth.

Key Details of the $155,000 Threshold

• Which wages count: Prior-year (2026) FICA wages shown in W-2 Box 3 from the employer sponsoring the 401(k) plan—not total household income and not wages from an unrelated prior employer.
• No FICA wages: If you had no FICA wages from that employer in 2026 (for example, certain self-employed or governmental employees not subject to Social Security tax), the mandatory Roth rule does not apply.
• Base $25,500 is still your choice: The mandatory Roth requirement applies only to the catch-up portion above $25,500 ($8,500 for 50–59/64+, or $11,750 for 60–63). You can still make the first $25,500 pre-tax.
• If your plan does not offer Roth: High earners subject to the $155,000 rule cannot make catch-up contributions unless the plan adds a Roth option.