You may have terminated participants in your qualified retirement plan who are zero percent vested in their account balance. How long do you need to keep them in the plan as plan participants? The plan document should have language which clarifies when to forfeit a non-vested account balance for a terminated participant. The most common forfeiture language that we see states that a forfeiture of non-vested balances occurs after the earlier of five consecutive one-year breaks-in-service or distribution of the vested account balance to the terminated participant. A break-in-service is usually defined as a plan year in which a participant worked less than 501 hours of service.