My husband was married to a woman who repeatedly cheat on him during their marriage and she had 2 kids. He has been paying child support for the 2 kids since their divorce 10 years ago. The children are teenagers now. My husband wants to get a paternity test because he recently saw pictures of the children (the mother left the state of California where they all lived at the time and has been hiding the kids from him ever since). Anyway he recently found where they live in Philadelphia, and saw some pictures of the kids and both kids look completely different than each other and neither of them look like my husband so this led him to wonder if he actually fathered the children.

I called our local child support office to see if he can get the process started for a dna test (we live in Illinois now) and the lady who answered the phone said that my husband needs to get a lawyer because the kids are over 2 yrs old. I don't understand why it matters how old the children are if they weren't born in Illinois, and we don't have a child support case with Illinois. The case is with California. What does he need to do to get a paternity test done? Does he have to file the papers with his local child support office or in Philadelphia where the kids now live?

If the original support order was issued in CA and he still lives in CA, then CA has jurisdiction.

The reason he was probably told about a 2 yr limit is that he may not be able to challenge it as this time. I assume they were married when the children were born and that he signed their birth certificates. That means he accepted his role as their legal father. I believe CA has a time limit within which he can challenge paternity. I believe that window is less than 10 years. So its possible that a paternity test, even though negative, would not change the support order.

As for the mother "hiding" the children from him, what has he done about that? If she moved without permission of the court and is hiding the children, that is prosecutable as parental kidnapping.

I believe CA has a time limit within which he can challenge paternity. I believe that window is less than 10 years.
Yes - the time limit is two years

And thus the issue, unless he challeged it within a certain amount of time, he may not be able to. He will need an attorney to see if there is any way to do it

Yes - the time limit is two years

Hence the two years the person mentioned. Its not how old the kids are, but how longer he has been their legal father.

I missed that you are in Illinois now. That means that the courts where the child now resides would have jurisdiction. But the CA laws would still apply.