Employee vs. Employer Contributions
In 401(k) plans, both employees and employers can contribute. But not every dollar is treated equally. Many plans set up employer contributions (like matching funds) on a vesting schedule, where ownership “vests” over time. This matters because if some of those employer contributions are not fully vested, they might not be included in the divided account.
This is why your QDRO must outline whether the alternate payee (usually the spouse receiving a share) should receive a portion of just the vested balance—or unvested employer contributions if they later vest. Often, plans will NOT go back and recalculate after vesting improves unless specifically ordered to do so.

