Employee vs. Employer Contributions
Most 401(k) plans include both employee deferrals and employer contributions. Employee contributions are fully vested immediately, but employer contributions may be subject to a vesting schedule. That matters in divorce—because you generally can’t give away what isn’t vested.
If you’re the non-employee spouse receiving a portion of the account, your share may only include employer contributions that are vested as of the date of division (or as defined by your divorce decree). Everything else may be lost unless your attorney carefully addresses these details in the QDRO.

