她结婚20多年，老头的401K应该是共同财产，有她一部分，由她决定；除非婚前协议写明

Example:

• If a spouse had a 401(k) worth $100,000 before marriage and it grows to $300,000 by divorce, the $200,000 growth (plus interest/earnings) is generally community property, while the original $100,000 is separate property.