Employee and Employer Contributions
Most 401(k) plans include both employee and employer contributions. While employee contributions are generally 100% vested immediately, employer contributions may be subject to a vesting schedule. If the employee spouse hasn’t worked long enough to fully vest in the employer match, some of that money might not be available for division.
Your QDRO needs to spell out whether it’s dividing the total account balance or just the vested portion. Otherwise, you might be asking for a share of funds that will later be forfeited, adding complications for both parties.

