This study investigated the lived experiences of 10 Filipino science teachers implementing the NGSS during School Year 2025–2026. Guided by a qualitative descriptive phenomenological design, the inquiry included teachers with at least 1 year of experience implementing NGSS. Data was obtained through in-depth, audio-recorded interviews and examined using Colaizzi’s seven-step phenomenological method. The participants’ experiences reflected a gradual reconfiguration of science teaching practices. Instruction increasingly incorporates inquiry, hands-on activities, collaboration, and connections between scientific concepts and learners’ experiences, moving beyond predominantly teacher-directed approaches. This transition was not without difficulty. Teachers encountered differences in student readiness, challenges in aligning assessments with the NGSS, limited instructional resources, and increased workload. In responding to these conditions, they drew on scaffolding, differentiated instruction, collaborative learning, reflective lesson planning, and continuing instructional support.

The analysis further indicated that NGSS implementation was influenced by the professional environment in which teachers worked. Collegial collaboration, administrative assistance, professional learning groups, and mentoring created avenues for sharing experiences, reconsidering instructional decisions, and working through implementation concerns. The findings thus position curriculum implementation as both an individual and organizational undertaking, with teachers’ knowledge and skills interacting with the professional support available within their school. These findings informed the development of the Proposed Enhancement Mentoring Framework for NGSS Implementation. The framework provides a sustained, collaborative, practical, and context-responsive structure for professional support designed for Filipino science teachers working in multicultural international school settings. Its proposed components focus on strengthening pedagogical competence, professional confidence, reflective practice, and continuing professional growth while supporting the development and maintenance of meaningful NGSS-aligned classroom practices.