Is this being performed by an outside clinician or is it by a school based clinician? If it's school based, then it's not billable to the child's carrier as this is covered under IDEA as a part of the child's IEP.
If this is an outside source, coming to the child's school you really can't use those codes as these are "...for patients who present with primary physical illnesses, diagnoses or symptoms and may benefit from assessments and interventions that focus on the biopsychosocial factors related to the patient's health status."
SBBH services are usually one on one, as if it were taking place in the clinicians office. I would use 90801 for initial interview. Further analysis could be coded as 90845. If the clinician is observing the child in a classroom environment then 90882 could be used. All of these would have a place of service of 03 "A facility whose primary purpose is education."
I hope this helps you. I have a child who is getting SBBH services through the Department of Education with a clinician on campus daily. Send me a direct message if you need further clairification. Good luck to you!