Employee and Employer Contributions
The 401(k) account typically includes both employee deferrals (what the participant contributes from their paycheck) and employer contributions. These two may have different rules, especially regarding vesting. A QDRO should make clear whether the alternate payee is getting a percentage of the total account balance as of a certain date, or specific types of contributions only. For example, some divorcing couples agree to split only the vested portion of the employer contributions.

