there is a difference between ABA and ABA-Discrete trail protocols. Not all schools do discrete trial training, but all do ABA (applied behavioral analysis) whether through daily programing or FBA(functional behavoiral assessments). If you ever come across a school that does not say they use ABA for instruction of students with autism, I would tell them they are looking for a lawsuit. Nearly all educational interventions for autism are based and/or share principals of ABA. Not to mention more and more educational approaches in general are seeing the potential that ABA programming helps literally everyone.

I would imagine ALL the public schools use ABA (discrete trial and/or verbal behavior) as parts of their programs. It is impossible for school disctricts defend NOT providing ABA based programing for students with autism. That said most public schools use a variety of approaches because each child is individual and discrete trial does not help every one. I would contact the schools you are interested in directly, ask to speak to their special ed and autism cooridinators/supervisors and also meet with potential teachers. Some school districts have "day schools" with more one-on-one discrete trial type instruction for the most severe cases/behavioral concerns you would be able to find more info on if they have this on the district websites. good luck.