Gateway testing is an important pedagogic tool employed by many university mathematics departments in calculus and precalculus courses. With a goal of ensuring that students attain needed basic skills in courses with a conceptual "reform" orientation, these tests provide an efficient means of assessing a large volume of student work, while at the same time motivating students to engage in the needed skills-based practice. In this article, we describe our experience over the past decade in utilizing a version of this idea, which we call "Mastery Exams," in the context of small liberal arts institutions. We discuss students' experience of autonomous mastery goal attainment inherent to our approach in the context of Self Determination Theory applied by educational psychology researchers in a number of higher education settings. We describe the implementation of these exams in the small-class-size setting and present data from a small study carried out at Washington & Jefferson College in 2012. We found that students in the Mastery Exam group showed significant gains in a pre/post-test of nonroutine calculus tasks compared to the non Mastery Exam group.