Kelley is а pаrticipаnt in his emplоyer-spоnsоred ROTH 401(k) plan during part of the year. Later in the year, Kelley becomes a participant in his new employer’s 403(b) plan. Kelley can defer an aggregate maximum of $23,000 (2024) (plus $7,500 if age 50 and over) between 401(k) plan and the 403(b) plan.