People may argue about the specific cutoff, but you're already aware that higher numbers are better. Some med schools have specific criteria they're looking for, but GPAs are not all made alike. A GPA at a school that inflates grades is much different than one that rarely gives 4.0 to anyone. Med schools know this better than anyone. The transcript they pass on usually has a breakdown of the grading scheme so residencies can directly gauge how difficult it was to procure higher grades. One of the big reasons we use horrible standardized tests like the MCAT is that it (theoretically) levels the playing field.