Background: Professional identity is the expected outcome of nursing educational institutions that is reflected in the values, beliefs, attitudes,and behavior of nursing alumni as professional nurses. Professional identity development is influenced by many factors and occurs dynamically and requires a long time from nursing education to a career as a professional nurse. Objective: This study aims to explore the experience of developing professional identity in Ners alumni at Universitas MuhammadiyahYogyakarta (UMY). Method: This qualitative research used a descriptive phenomenological approcah. The purposive sampling method used in the selection of informants totaling seventeen alumni. Data collection used in-depth interview with whatsapp video call for 60-90 minutes. Data analysis used Colaizzi method and Nvivo 12 Plus Results: The finding showed that four themes and 13 categories in one core variable of professional identity development of Ners akumni UMY that follows the pattern of nurse career development namely: 1) Identification of self-professional, 2) Integration of Professional identity, 3) Supporting the development of nurses professionalism, 4) Obstacles of the development of nurses professionalism. UMY ners alumni have various roles as professional nurses in nursing careers. Factors that support and hinder professional identity development come from personal, family, institutional, social and cultural factors. For UMY Ners alumni, the development of professional identity is internalized through Islamic values and beliefs, nursing professional values and working as professional nurse. Conclusion: Professional identity development of UMY Ners alumni follows the pattern of nurse career development.