Can there be an adjustment to child support for the parent who has never paid child support because he has been in jail and rehab center for 12 years? Right I owe over $40,000.

A person can not just "give up parental rights" the other parent will have to agree to it, and almost always there has to be a new parent to adopt the child.

The person should have asked for the reduction. But yes, they can ask the court to review and consider that fact. Now most states have a min due, it may be 30 or 80 a month that would be owed, but if there was no income it is low.

You will need to hire an attorney and file to modify the support order