Are 401(k) plans and cash balance plans subject to RMDs?

The RMD rules apply to IRAs and all company-sponsored retirement plans, including 401(k) profit-sharing plans, defined benefit plans, and cash balance plans.

However, RMDs only apply to vested account balances. So, if you have 3-year vesting, your RMD will only be on the vested portion.

The RMD rules still apply to Roth 401(k) plans. However, the RMD rules are not applicable to Roth IRAs when the individual owner is still alive.