My ex of 13 years is now asking for equity out of a house he's had nothing to do with in that time. He's on the deed.

More facts are needed here, but if you were divorced 13 years ago and your ex's name is still on title to the house (I assume with yours), then either the division of the house was not addressed by the court (i.e., it is not discussed in the Judgment), or it was and what was supposed to happen didn't (for example, if the house was awarded to you in the divorce, and no one ever had your ex sign an interspousal Transfer Deed (or similar document) to effect the release of his interest in the house to you). In the first situation, if the houses were never addressed in the divorce and there was a community interest in the house, you have an "omitted asset." Under the California Family Code (sec, 2556), you can file a Request for Order ("RFO") with the court, bring to the court's attention that you and your ex forgot to adjudicate the house, and ask the court to do that and distribute this omitted asset as appropriate. I assume you have made all the mortgage payments for the past 13 years, and under the law, you will get credit for that.

This can be a complicated situation, so if you can afford to hire a lawyer to help you, I strongly recommend doing so. If not, most courthouses have a family law self-help center. They cannot give legal advice (which I think you will need), but they can help you fill out the forms and file them with the court. Once filed, the court will schedule a hearing about 45-6 weeks out. Your ex has the right to oppose your request, and there are time deadlines for seeking relief like this, so be aware of them. Best of luck with this matter.