According to state law, a student receiving a certificate of achievement or completion has the right to participate in graduation ceremonies and any school activity related to graduation. [Cal. Ed. Code Sec. 56391.] Districts, may, but are not required, to award a certificate of achievement or completion. [Cal. Ed. Code Sec. 56390.] However, if participating in graduation-related activities is specified  in your child’s IEP (as part of his participation in integrated activities at school), the district must implement the IEP and allow him to participate in the graduation activities whether he is receiving a certificate of completion/achievement or not. You should address this participation in the IEP, beginning with your discussion of transition, at age 16 or younger. This will ensure enough time to take any necessary action to resolve disagreements before the graduation ceremony.