In Thailand, the National Health Security Office made a notable attempt to introduce the QOF under the Universal Health Coverage (UHC) at the end of 2013. After the establishment of the QOF, the program was implemented nationwide. There are concerns that the quality indicators used in the Thai QOF have not been developed in a systematic, participatory and evidence-based manner. Without supportive evidence, the quality indicators cannot guarantee the health impact. Furthermore, there are variations in the implementation and financing of the QOF by different geographical regions. At the request of the NHSO, this study will be conducted to review the current QOF program for further improvement; to revise and retire existing quality indicators, if appropriate, as well as to develop new indicators that are evidence-based; to provide recommendations for effective QOF program management, implementation, monitoring and evaluation. This study will employ qualitative (self-administered questionnaires, in-depth interviews and focus group discussions) and quantitative (secondary data analyses) techniques in order to address the aforementioned objectives.