This paper assesses impacts and constraints of the implementation of universal coverage (UC) in Thailand's public health system so far in selected provinces of the northeast region. Based on incidence and findings discovered in the survey, we can draw out a depiction to explain linkages and systematic consequences of the situations from the Primary Care Units (PCUs) to secondary and tertiary level hospitals. The depiction simply describes the current situation and the impact of UC on the whole system of care provisions with specific constraints at each facility level, and illustrates the systematically negative cyclic consequences of those constraints. Due to the "primary constraints" at all facility levels - mainly because of a shortage of health workers and inadequate budget financing - the Sarng-Nam-Sorm (health promotion and disease prevention ahead of curative health care) and Klai-Baan-Klai-Jai (Health facility near dwelling) strategies of the UC policy face failures at the PCU level, which, as a result, do not reduce, but rather increase number of the patients at the hospital level. Unbearable workloads and poor equipment with a lack of specific needed professionals at most secondary level hospitals at the district level has tended to push them to more often refer inpatient cases to tertiary level hospitals in the provincial cities because it is better and safer for patients. This is often viewed by the tertiary level hospital as over-referral, and puts a tremendous burden on them in terms of physical workloads and financial cost. In this study, we explained that these impacts from facilities in lower levels to those at higher levels are "linking consequences", which will eventually negatively result backward on the lower level facilities in terms of "secondary constraints". In the long run, if no attempt is made to ease the constraints and improve the situation - mainly regarding the inadequacy of the health workforce and funding- this vicious cycle of negative consequences could collapse the whole public health care system and UC., この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。