1. Employee and Employer Contributions
Most 401(k) plans—especially in the general business sector—include both employee deferrals and employer matching contributions. Only the amounts contributed (and investment growth) during the marriage are typically included in the marital estate. Contributions made before the marriage or after separation might be excluded, depending on state law.
Employer matching contributions may also be subject to a vesting schedule, which could affect how much is actually available to divide. Unvested funds generally remain with the employee spouse. Be sure your QDRO clearly outlines how to handle partially vested accounts and what happens if shares become vested later.

