This policy brief shows that although there are available national assessments that can provide evaluation data to determine Mother Tongue-Based Multilingual Education (MTB-MLE) effectiveness and efficiency, there is still no current formal and large-scale program evaluation that spans various program components and identifies which ones contribute to student achievement. The government should craft a comprehensive policy on MTB-MLE program evaluation that synthesizes available assessment data and program evaluation results. Such an evaluation can be done on a macro (national) and micro (school and division) level, with the latter informing the former. The results should be disseminated nationally and internationally to contribute to local and international MTB-MLE research and practice.