The purpose of this qualitative descriptive study was to explore how high school teachers describe problem-based learning as an instructional model for student learning in various academic disciplines in the United States. The research was grounded in constructivist learning theory and Problem-based learning (PBL). The study addressed two research questions RQ1: How do teachers describe the use of PBL as an instructional model for student learning in different disciplines? and RQ 2: How do teachers describe the benefits and shortcomings of PBL as an instructional model in the discipline they teach to enhance student learning? The sample consisted of N = 23 full-time licensed high school teachers who use PBL in their classrooms. The teachers were recruited using convenience and snowball sampling techniques. The two data sources were one-on-one semi-structured interviews (n=12) and two focus group interviews (n=6, n=5). The data were analyzed inductively using Braun and Clarke's (2022) six phases of thematic analysis. A codebook was developed to capture steps in the analysis process. The study revealed six themes that answered the research questions. RQ1: (1) purposeful learning experiences, (3) building and sustaining student agency, (4) equitable access to disciplinary content, and (5) collaborative engagement. RQ2: (2) transference of knowledge and skills and (6) perception of teaching and learning. Teachers described the benefits and shortcomings of using PBL in their academic disciplines. They shared insights on implementing PBL effectively to create a student-centered academic environment and encourage student ownership of learning. [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.]