Employee and Employer Contributions
The QDRO must clearly distinguish between employee contributions (usually fully vested) and employer contributions (which may be partially or fully unvested depending on service time). In many cases, only vested amounts can be divided, but the plan might allow conditional awards based on future vesting.
For example, if the spouse is awarded 50% of the marital portion, and employer contributions were only 60% vested at the time of divorce, the unvested portion might be forfeited unless explicitly accounted for in the QDRO design.

