Several people ask about whether or not P/F grades or S/U grades count towards the GPA and most people say they don't, but several on here and from outside sources alike tend to feel that AMCAS gives an actual inputted grade when an F or a U is obtained from one of these grading options, and thus lowering the student's GPA. I think there is another school of folks that mention AMCAS just taking note of the F or U attained in an ungraded course and potentially look at that with negativity, but that's as far as it will go, as the GPA will remain untouched. At my school P/F is not a grading option, only S/U, potentially just a same-difference set of words, but neither count towards the GPA. From what I am reading, I believe that the grade is noted, but that it does not inhibit one's GPA. I am taking a course S/U right now because I wanted to take a very advanced course and didn't have all the background, its a post-doc type of course.