Background: China has achieved universal coverage, with a higher rate of 95% medical insurance. However, huge inequalities are concealed under universal coverage. This article aims to explore the medical insurance utilization disparities over different insurance schemes, regions, and socioeconomic statuses (SES). Methods: This study was based on an open-access dataset in 2010, 2012, 2014, and 2016. A longitudinal analysis and separate logistic models were performed. Results: Urban Employee Basic Medical Insurance (UEBMI) members had an outstanding advantage in specialist visiting over those on the Urban Resident Basic Medical Insurance Scheme (URBMI) (OR = 0.607, p < 0.001) and New Cooperative Medical System (NCMS) (OR = 0.262, p < 0.001). However, in terms of a doctor visiting if a person is sick, the odds of patients in the NCMS receiving a visit were 55.1% ((OR = 1.551; p < 0.05) higher than those on the UEBMI. Compared with west China, the odds of those in the north-east and east were 2.1% (p > 0.05) and 97.2% (OR = 1.972; p < 0.001) higher for seeking medical treatment if sick, and 10.8% (OR = 0.892; p < 0.01) and 42.7% lower (OR = 0.573; p < 0.001) for a specialist visiting. In terms of SES, for each unit of increase in the Standard International Occupational Prestige Scale (SIOPS), the odds of seeking medical treatment decreased by 4.3% (OR = 0.958; p < 0.05), and the odds of a specialist visiting increased by 17.1% (OR = 1.171; p < 0.001) for each unit of the annual income logarithm. Conclusions: NCMS members and residents in west China were in a disadvantage status in terms of access to specialists, though had a higher probability of medical care if sick. SES variables were positively correlated with a specialist visiting consistently. We suggest a further focus on healthcare quality in the west and rural areas.