I raised 3 kids on my own. I separated from their father in 1996 and moved to Texas. Filed for child support and every time they tried to garnish his wage he woulkd take off to Mexico for a few years and then come back (he lives in Colorado and I live in Texas). When I would find out I would file again and he would take off to Mexico again. Finally, I just gave up on help and raised my kids whom at that time were 2, 4 and 6 yrs old now they are 18, 20 and 21. I practically raised my kids alone for 16 yrs and now I find out the father is back in the states (Colorado) hs become a US citizen and legalized his wife and kids that he had in Mexico. My question is can I go back and try to get him for back child support after all this years.
Thanks

Yes, you do not "file" again, merely go back to the court where the current child support order is from and use that order, it is still in place and can be enforced