This study aims to identify the difficulties faced by students in designing Modul Ajar during their Teaching Practice Program (PPL) in schools. A qualitative research method was employed to provide a comprehensive understanding of the challenges faced by students when creating lesson plans under the Kurikulum Merdeka. The difficulties identified include: 1) challenges in initiating the design of the Modul Ajar, 2) analyzing learner needs and conducting assessments, 3) adapting the curriculum, 4) developing learning indicators and objectives, 5) selecting appropriate teaching methods and media, 6) designing assessment tools, 7) integrating differentiated instruction, 8) managing resources and time, 9) sourcing references and inspiration, 10) incorporating mentor feedback and consultations, and 11) engaging in reflective practice for future development. In conclusion, the process of developing Modul Ajar is a complex and demanding task. PPL students encounter significant challenges, including the need to balance theory and practice, limited time and resources, accommodating student diversity, and the complexity of creating a comprehensive assessment system for effective Modul Ajar in line with the Kurikulum Merdeka