Private school tuition and fees are not deductible. You can only deduct the portion that relates to medical expenses. Your son or daughter’s therapist appointments should be deductible as a medical expense, according to IRS Publication 502, but only to the extent it is for medical care. You would claim these expense on schedule a and itemize your deductions.
Boarding school fees are considered a non-deductible expense by the IRS. Please view the link below for more information.
https://atlas.md/content/upload/files/IRS%20Code%20Eligible%20Medical%20Expenses.pdf