The transformation of Private Islamic Higher Education Institutions from institutes into universities represents a strategic policy that extends beyond administrative restructuring to encompass institutional identity, governance, and socio-religious functions. This study aims to analyze the transformation process of PTKIS in East Java and examine how institutional distinction, knowledge integration, and religious moderation are developed as strategic pillars of post-transformation institutional development. A descriptive qualitative approach with a multi-case study design was employed, involving three universities: Universitas Nurul Jadid Paiton Probolinggo, Universitas Ibrahimy Situbondo, and Universitas Zainul Hasan Genggong Probolinggo. Data were collected through participant observation, in-depth interviews with university leaders and transformation teams, and document analysis of institutional policies and government regulations. Data were analyzed iteratively using the Miles, Huberman, and Saldaña interactive model. The findings reveal that institutional transformation is a multidimensional process comprising organizational restructuring, governance reform, and cultural adaptation rather than a mere change of institutional status. The three universities developed different forms of institutional distinction rooted in pesantren values, while simultaneously integrating Islamic and general sciences through interdisciplinary curricula and strengthening religious moderation through academic, student, and community engagement programs. More importantly, this study proposes a Pesantren-Based University Transformation Model, demonstrating that sustainable institutional transformation follows a sequential pathway: Institutional Transformation, Institutional Distinction, Knowledge Integration, Religious Moderation, Academic Competitiveness, and Social Harmony. This model constitutes the principal theoretical contribution of the study by explaining how pesantren values function as strategic organizational resources for strengthening institutional competitiveness without diminishing Islamic identity.