Traditional vs Roth Accounts
If the participant has both traditional and Roth 401(k) accounts, they must be treated separately in the QDRO. Roth accounts are not taxed upon withdrawal (if certain conditions are met), while traditional 401(k) account distributions are generally taxable.
Failing to identify Roth versus traditional balances in the QDRO can result in the alternate payee receiving the wrong tax treatment or delays in processing by the administrator.

