Employee vs. Employer Contributions
401(k) plans consist of both employee contributions (money the participant directly defers from wages) and potentially employer contributions, such as matching or profit-sharing allocations. In most cases, all employee contributions are immediately vested, but employer contributions may be subject to a vesting schedule.
A good QDRO will separate employee and employer contributions if necessary and divide only the marital portion. For instance, if the employer’s matching contributions aren’t fully vested at the time of divorce, the alternate payee may not receive those funds unless they later vest and the QDRO includes language allocating them.

