After two bills passed in 2004 and 2011, a nation-wide social insurance in Indonesia has formally established. Aiming at a universal health coverage in 2019, the Jaminan Kesehatan Nasional (JKN) will cover almost 260 million Indonesians and be one of the biggest single payer national health insurance scheme in the world. Our research attempted to investigate whether justice, trust to health care services, confidence level of health system, political party support and evaluation of health care services post-JKN affected policy acceptability in our health workers (N=95) and laypeople (N=308) sample. A-two level multilevel modelling in our health worker sample revealed that justice negatively correlated to policy acceptability, while confidence to health system and institutions as well as evaluation of health care service post-JKN yielded positive correlation. In our laypeople sample, trust to health care service and evaluation of health care service post-JKN were positively affected policy acceptability. In this paper, we discussed why justice matters to a positive policy acceptability for health workers, but not for laypeople. We also discussed the possibility of laypeople's pragmatic motives of joining JKN scheme.

Key words: justice, policy acceptability, social health insurance, trust