Legal Question in Family Law in Texas

Your father may have designated alternate beneficiaries in the 401K, in which case it would have passed to those alternate beneficiaries. Otherwise, the account became part of his estate when he died. If he left a will, it would pass under the terms of the will.

If there was no will, it passes under the Texas Laws of Intestacy. Contributions and earnings made during his remarriage are community property and pass under the laws of intestate succession for community property.

Contributions and earnings made during the marriage to mom, were community property with dad and mom. The documents governing mom's estate should be reviewed to see how her community share of the plan was covered. Contributions and earnings before the remarriage are dad's separate property and pass under the law of intestate sucession for separate property.

This is a complicated situation and these laws can be complicated. You should consult an attorney specializing in wills and estates to assist you.