OBJECTIVES: This study is the first rigorous evaluation of the impact of Jaminan Kesehatan Nasional (JKN) on improving access to outpatient and inpatient care, utilising longitudinal data from the Indonesian Family Life Survey. METHODS: Two treatment groups were identified: a contributory group (N = 982), who paid the premium voluntarily, and a subsidised group (N = 2503), paid by government. Each group was compared with the uninsured group (N = 8576). Propensity score matching combined with difference-in-difference approaches was used to estimate the causal effect of the JKN programme. RESULTS: The results found that JKN increased the probability of inpatient admission for the contributory and subsidised groups by 8.2% (95% CI 5.9-10.5%) and 1.8% (95% CI 0.7-2.82%), respectively. The contributory group had an increase in probability of an outpatient visit of 7.9% (95% CI 4.3-11.4%). CONCLUSIONS: The JKN programme has increased the utilisation of outpatient and inpatient care in the contributory group. Those with subsidised insurance have an increase in access to inpatient facilities only, and this is of a smaller magnitude. Hence, while JKN has improved average utilisation, inequity in access to both outpatient and inpatient care may remain.