Legal Question in Family Law in California

Absent an order for some other deadline, child support ends the day of graduation. It's not anyone's "job" to find that out, but it is certainly in the interests of the support payer to know, and the support recipient probably would want to know too. You don't need any new order to end the support, although if the case is being handled through the Department of Child Support Services, you would probably want to coordinate with them and submit anything they might require to establish that support is done.