Objective  To study the effect of New Rural Cooperative Medical Scheme (NRCMS) adjustment on health service utilization among rural residents in Ningxia Hui Autonomous Region (Ningxia).

  Methods  We extracted the data on 38 804 rural residents over the age of 15 years from the dataset of four waves of household survey conducted in 2009, 2011, 2012 and 2015 in four counties of Ningxia; the surveys were a part of the pilot medical reform project – “Constructing an Innovative Payment System and Improving Health Performance”. Difference-in-differences model was used to analyze the effect of NRCMS adjustment on residents’ health service utilization.

  Results  Significantly decreased rate of visiting a doctor during two weeks (odds ratio OR = 0.783, 95% confidence interval 95% CI: 0.632 – 0.969) was observed among the participants in the two counties with the NRCMS adjustment in 2012, one year after the implementation of the adjustment, compared to that among the participants in the two counties without the adjustment; significant increase in yearly hospital admission rate (OR = 1.231, 95% CI: 1.014 – 1.493) was also observed among the participants in the two counties with NRCMS adjustment in 2015, five years after the adjustment implementation, in comparison to that in the two counties without the adjustment.

  Conclusion  Among the rural residents in Ningxia, the adjustment in New Rural Cooperative Medical Scheme had a negative impact on the rate of visiting a doctor during two weeks significantly one year after the adjustment but the effect of the adjustment on hospital admission rate was of significance five years after the adjustment and the persistence of the effect needs follow-up study.