Employee vs. Employer Contributions
401(k) plans commonly contain a mix of employee salary deferrals and employer profit-sharing or matching contributions. In divorce, both sources are typically divisible, but only vested portions of employer contributions are eligible for immediate division. Unvested portions remain with the participant unless and until they vest under the terms of the plan.
Be sure to clarify in the QDRO that division applies only to vested amounts unless both parties agree otherwise. You should also ask the plan administrator for a breakdown of vested and unvested funds as of the agreed-upon date of division (usually the date of divorce or separation).

