Employee vs. Employer Contributions
Employee contributions to a 401(k) are always fully vested. Employer contributions, however, may be subject to a vesting schedule, which means the employee only earns the right to keep the employer portion after a certain number of years of service.
If an employee is not fully vested at the time of divorce, the alternate payee (typically the non-employee spouse) may receive only the portion of employer contributions that have vested. Unvested amounts are usually forfeited and can’t be divided in the QDRO unless otherwise negotiated.

