We have been divorced for about 4 years now. He moved to a different state after getting out of jail(a 9 month sentence ending with a felony on his record) because I kicked him out for using drugs while on probation and living in my house. He comes to pick up our two boys one summer, then a week or two later calls me and says he wants their SS cards and birth certificates because they were going to stay there and go to school. Can he legally do that when we have joint custody? What can I do to get them back in my state?

No he can't do that if you have joint custody, moving the children out of state would require a custody hearing and a modification of the custody agreement, I recommend you get a lawyer and do not send their ss cards or birth certificates. Since your ex has a felony on his record you will likely be given primary custody of your children.

We have been divorced for about 4 years now. He moved to a different state after getting out of jail(a 9 month sentence ending with a felony on his record) because I kicked him out for using drugs while on probation and living in my house. He comes to pick up our two boys one summer, then a week or two later calls me and says he wants their SS cards and birth certificates because they were going to stay there and go to school. Can he legally do that when we have joint custody? What can I do to get them back in my state?

"One summer"? How long ago was this?

You say you have "joint custody". Is the divorce decree any more specific than this? Because "joint legal custody" and physical custody according to a fairly detailed schedule is the norm.

And it' always a good idea, especially in family law matters, to tell you what state you are in. Laws vary from state to state.