If the participant has borrowed from their 401(k), this could significantly lower the account’s actual value. The plan administrator generally subtracts the loan amount from the total balance when determining what the alternate payee is entitled to.
Your QDRO should clarify whether the alternate payee’s share is calculated before or after subtracting the loan. This decision can lead to a difference of thousands of dollars. For example, if the marital value of the account was $100,000 and there’s a $20,000 loan, the 50% share could be based on either $100,000 or $80,000—depending on the QDRO terms.