The research article focuses on Out-of-field teaching that demands urgent attention from school leaders and administrators due to its impact on instruction quality and student learning particularly in Leyte Division, Philippines. This study describes the challenges as well as the coping mechanisms of out-of-field mathematics teachers. The phenomenological approach was employed to examine the experiences of fifteen senior high school math teachers. Data were gathered through in-depth interviews, digitally recorded, transcribed, and was analyzed using the Moustakas method. The results showed that mathematics educators faced challenges when teaching subjects outside their expertise due to lack of content and pedagogical knowledge, resources, student motivation, and training. Despite this matter, they overcame these circumstances through self-learning and adaptive methods. This study determined that teaching subjects without adequate knowledge was problematic as it created interconnected problems. Effectively, a retooling and mentoring program led by subject experts would be beneficial in improving the content and pedagogical knowledge of out-of-field teachers. Meanwhile, school leaders and administrators may conduct profiling to identify the needed teachers and should allocate more school funds for teaching, learning resources, and other materials necessary for instructional delivery