Lyman Briggs College is a small residential college within Michigan State University, devoted to preparing students for STEM careers via preparation in the biophysical sciences that is paired with the humanistic and social scientific study of science and sciences humanistic and social dimensions. This paper reports and interprets the quantitative outcomes of an ongoing NSF-sponsored S-STEM project, begun in 2009, seeking to improve STEM retention in the college via a combination of scholarships and cohort-based curricular and cocurricular activities. The program supported scholars in their second through the fourth year. In examining the over 90 participants against a comparison population (eligible students who did not participate in the program), there was no statistical change in graduation rates from Michigan State University, though there was a statistical increase in retention in STEM majors. Moreover, the program has shown success in closing some inequitable STEM retention gaps between demographic groups with more or less social privilege (especially students with high financial need and students with low precollege math preparation), while not closing others (for underrepresented racial and ethnic minorities).