This study measured students’ reading ability and gathered basic demographic information from children and teachers. Some standard context information was also gathered from children about their exposure to reading in the home. Thus, the data allow us to describe one outcome of the current schools sampled—children’s reading ability—but they do not provide any empirical measurement of the inputs that contribute to this outcome. To explain the current state of reading performance as measured by this study, we must rely on other contextual data from our concurrent Language Usage Study and general knowledge of mother-tongue-based multilingual education (MTB-MLE) implementation, as documented by policy and other studies carried out by other researchers. In the absence of direct measurement of “implementation fidelity” to a particular reading instruction program or materials, we must also rely on global evidence of how reading skills develop in alphabetic languages. To put it simply, children can learn to read, but only if they are taught to read. Teachers can only teach reading if they have been prepared to do so through training and are equipped with appropriate materials. Teachers and students must be present and making productive use of class time. The purpose of using EGRA as a system diagnostic is primarily to establish a baseline against which future progress can be measured and to identify priority areas for instructional improvement and teacher training. Cite this report: Betts, K., Punjabi, M., Pouezevara, S. & Cummiskey, C. (2019). 2019 Regional Early Grade Reading Assessment (EGRA): Bahasa Sug, Chavacano, Magindanawn, and Mëranaw. Prepared for USAID under the All Children Reading-Philippines Project, AID-OAA-TO- 16-00017. Research Triangle Park, NC: RTI.