Quick Answer
Medical schools receive CASPer results directly from Acuity Insights, then decide for themselves how those results fit into their admissions review. There is no single universal CASPer policy across all medical schools.
That means applicants should be careful with simple claims like "CASPer is just a checkbox" or "CASPer is a hard cutoff everywhere." Either could be true at one program and misleading at another. The practical move is to treat CASPer as a required admissions component where applicable, complete the correct test type on time, and avoid building your application strategy around unverified assumptions about hidden weighting.