1. Employee and Employer Contributions
A common mistake during divorce is assuming the entire account balance is automatically marital property. But many 401(k) plans include contributions from both the employee and the employer. You need to identify:
- The total employee contributions (and their investment growth)
- Any employer matching contributions
- Which contributions were made during the marriage
- Which contributions are unvested
Only the marital portion—the amount earned during the marriage—should be divided unless your agreement states otherwise.

