This paper uses Advanced Placement (AP) exams to examine how receiving college credit in high school alters students' subsequent human capital investment. Using data from one large state, I link high school students to postsecondary transcripts from in-state, public institutions and estimate causal impacts using a regression discontinuity that compares students with essentially identical AP performance but who receive different offers of college credit. I find that female students who earn credit from STEM exams take higher-level STEM courses, significantly increasing their depth of study, with no observed impacts for males. As a result, the male-female gap in STEM courses taken shrinks by roughly one-third to two-thirds, depending on the outcome studied. Earning non-STEM AP credit increases overall coursework in non-STEM courses and increases the breadth of study across departments. Early credit policies help assist colleges to produce graduates whose skills aligns with commonly cited social or economic priorities, such as developing STEM graduates with stronger skills, particularly among traditionally underrepresented groups.