At what point does a Judge get involved re non-payment of child support?

Actually, if you are owed over $30,000 in support arrears, and your ex is lying about his income, you probably cannot afford to NOT hire private counsel to take him back to court.  The D.A. process is notoriously slow, inefficient, and lackadaisical, and you will not receive correctly-calculated interest, penalties, or attorney's fees.  For a discussion of most of those things, see the information posted and referenced at http://willicklawgroup.com/child-support/. Only private counsel will be able to get to the root of who-owns-what as to the corporation (the D.A.'s office will not investigate, will not subpoena bank or other records, and essentially does not care).  Proving someone was NOT unemployed requires getting, reviewing, and submitting bank and credit cared information.  Not simple, but normal operation for a family law specialist. On "medical issues," support can be deviated upward, depending on the facts; additionally, speak to qualified counsel as to whether the child is "handicapped" within the meaning of the law as to getting an order for post-majority support.