This study utilized constructivist grounded theory to examine teacher candidates' STEM confidence, preparedness, and self-efficacy before and after participation in an elementary STEM methods course. The study aimed to identify characteristics of the course that impacted teacher candidates' growth. Twenty teacher candidates and the course instructor consented to participate in the study. Course artifacts and interview transcripts were analyzed using the constant comparative method and themes were identified. Data analysis revealed teacher candidates' STEM confidence, preparedness, and self-efficacy to be positively impacted by participation in an integrated STEM methods course. The three main themes are: the Intersections of Theory, Constructed Experiences, and Practice, Assessment for Learning, and Instructor Intentions and Mindset. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]