Schools give out a mix of need-based and merit-based aid. The need-based aid is based on how much your parents make - you're still tied to them until you're like 30 or so I think, depending on the school. Merit-based aid is based on not only GPA and MCAT but how much a school wants you. If the school thinks that you'll be in high demand and they want you there, they'll extend you a merit scholarship and see if you bite. There's no automatic numeric threshold where if you're above that threshold you get an automatic scholarship - that I know of, anyway. So the key is to be a strong applicant that is highly desirable, which is what you should be aiming for regardless.