Box 12-AA — Code AA — Roth 401(k) deferrals
Designated Roth contributions under a section 401(k) plan.
What it means
Code AA Roth deferrals are included in Box 1 wages (they are after-tax for income tax) but still count toward the same elective deferral limit as Code D. Combined D + AA + similar codes cannot exceed the annual deferral cap.
Related glossary: 401k