This phenomenological study aimed to research the implementation practices in elementary schools of MTSS for Culturally Responsive SEL and its impact on students, within the first year of returning to school for full days of instruction after a 16-month interruption of in-person learning due to the COVID-19 pandemic. Semi-structured interviews were conducted for 21 participants, which included elementary school administrators, psychologists, and counselors. The interviews were designed to elicit responses that provided an understanding of the common experiences in the participants' implementation efforts of a school-wide, tiered structured support system for students in elementary school. The researcher sought to understand MTSS implementation efforts of SEL and CRT practices and their impact on student outcomes. The findings revealed six significant themes: (a) implementation efforts involve all members of the team, (b) MTSS for SEL is integrated into PBIS, (c) there was an increased need for social-emotional support, (d) SEL interventions and supports have an overall positive impact on students, (e) incorporating culturally responsive practices and SEL is emerging in implementation, and (f) traditional punitive practices are detrimental for effective implementation of MTSS for Culturally Responsive SEL. The implications in this study reveal that MTSS for culturally responsive SEL provides educators with the aptitude to address social-emotional and behavioral student needs in a systemic and structured approach. Furthermore, implementing MTSS for Culturally responsive SEL results in increased capacity and leadership for staff, and school-wide systemic structures that support student success, equity, and a positive school climate and culture. [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.]