You would think so, but it might not. Think about it for a minute. How is a big company going to keep track of when your child graduates from high school or turns 18? Your best bet is to go to HR several months before support should end and ask them what they want in order to stop withholding. I have seen some companies that do require a court order to cease withholding. If that is the case, you will need to talk with a lawyer.
