Guidelines for a 12-year basic education curriculum were announced and implemented in Taiwan in 2014. In these guidelines, “life curriculum” is defined as a course that is designed to bridge the gap in elementary and kindergarten course knowledge for first and second graders. Teachers should demonstrate adequate professionalism to fully implement the core literacies embodying the curriculum ideas of the 12-year basic education curriculum. This study aimed to develop a set of indicators for the professionalism of life curriculum teachers. Literature on Taiwanese and international studies was first reviewed to establish criteria for the professionalism of life curriculum teachers. The teaching capability maturity model was adopted, which divides professionalism into five levels, namely the beginner level, basic curriculum management, advanced curriculum management and implementation, quantitative management, and sustainable optimization, and incorporates 15 dimensions and 45 indicator checkup items. A modified Delphi method was adopted to obtain consensus among experts and scholars. A fuzzy hierarchical analysis was performed to assign weights and ranks to the indicators at all five levels. This empirical indicator system was therefore developed to serve as a self-assessment tool for life curriculum teachers to develop their professionalism; moreover, the indicators may serve as a reference for educational administrative agencies to promote the development of teacher professionalism and support future teachers.