Because students need 21st-century skills, this mixed methods study aimed to compare gifted service models and their effect on the development of student creativity in elementary school. The quantitative research phase was conducted through a pretest-posttest design using the "Torrance Test of Creative Thinking, Figural." Student participants received instruction for at least two years in the advanced content, cluster, collaborative, or resource gifted service model. The researcher analyzed pretest and posttest scores for fluency, originality, resistance to premature closure, elaboration, and creativity index with a one-way repeated measures ANOVA to show changes in component scores across the cluster and resource gifted service models. TTCT-F data from student participants in the advanced content and collaborative gifted service models were excluded from quantitative analysis to maintain internal validity. The qualitative phase explored the perspectives of the student participants' gifted teachers through semi-structured interviews, inclusive of advanced content and resource teachers. Data analysis showed that students in cluster service models grew in fluency, originality, resistance to premature closure, and creativity index scores. Teacher participants' perspectives revealed that social interactions unique to this service model may partially explain growth over time. Teacher participants reported that the use of engaging teaching activities, such as technology, project-based learning, and differentiated tasks, may also have cultivated growth in creativity. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]