Two transition points were studied: from intended college major as high school seniors to actual undergraduate major (Stage I), and from actual undergraduate major to intended graduate school major (Stage II). Persistence was defined as staying within the broad category of CEMP sciences. The descriptive findings showed net losses from the CEMP pool of students at both transition points and greater field switching for women both into CEMP sciences and out of CEMP sciences. The predictive findings for both transitions, using logistic regression with random coefficients, showed that student and university characteristics (entered jointly) were associated with field persistence for the majority of fields. Significant gender differences in field persistence remained for most, but not all, fields after controlling for student and university.