I recently won custody of my two sons. Since, My ex-husband signed up for disability.
How can I collect money for child support? He has been denied 3 times, and it has been
2yrs. I substitute teach, and my son needs braces. I need financial help.

You go back to court to have the support order enforced. How far in arrears is he? If it is over a certain amount you can contact an agency like support kids to help collect but if you haven't gone back to court to have the order enforced I would start there.

He is 2yrs behind, and diagnosed with stage4 lymphoma

If there is any way possible for you to obtain a life insurance policy on him, that may be the only way you will ever see a dime.

Given his diagnosis, that would not be an easy, or inexpensive endeavor.

Good Luck to you!

First off are you both on talking terms ? He may need a lawyer to get disability from the feds. If he gets it so do your children. What state are you in because many states now offer no or low cost dental and health insurance to children that reside in the state. Does he own property or anything ? Because he's in arrears then he might be willing to sign it over to you if his condition is fatal ( aka write you into a will or trust )

Your in an odd place because I realize that your not getting suppert but on the other hand what he has may very well be fatal so its not something you throw the weight of the courts behind chasing him to the grave.
Prognostic Indicators

Maybe we could help you find resources that could aide in your needs if you can identify the state.

We live in Georgia. He has stage 4 lymphoma. I definitely don't want to "chase him to the grave!" We don't speak due to a new wife who is 26yrs younger, he just adopted her 3 kids. Now what?

You take him to Court - either to modify or enforce the support order.