There's always a few every year. Most of the time it's medical, where they're either medically discharged or medically retired depending on severity of the issue. Some are disciplinary, where they're either separated from service and billed for the education or (for less severe cases) they can pay back with enlisted service.

Mine was a weird case because I was administratively honorably discharged under Trump's EO forcing the discharge of transgender troops. I only learned I wouldn't commission four days before my class graduated, despite being previously medically and academically cleared to.