Legal Question in Family Law in California

Very unlikely. If it was listed in community property, it was most likely included in the property division calculations already. Not everything gets split in a divorce, particularly things that are more connected to one person than the other, even though they are community property. A distribution from a 401k, while possible, creates accounting and tax issues. So, for example, if there is $50,000 in a 401k, and $30,000 in a stock brokerage account, and $5,000 in a checking account and $5,000 in a savings account, and a paid off car worth $15,000, it would be very common to give the 401k to the person who is the named account holder, plus $2,500 from the savings account, and give the other assets to the other spouse, to create an equal division of $52,500 to each spouse. So unless it was left out of the calculations entirely, you aren't owed a share of it. If it WAS omitted entirely, then you could file a motion for allocation of omitted assets, using the original case title and number.