The following study, titled The Mobilization for Inter-Agency Collaboration and Citizen Engagement for Developing a Primary Care System for Provincial Administrative Organizations: A Case of Khon Kaen Provincial Administrative Organization (KKPAO) project, has four primary aims. The first is to study the preparedness of the primary health system of KKPAO in the oversight of primary health services by the Sub-district Health Promotion Hospitals (SHPH) that have been transferred from the Ministry of Public Health (MOPH) to the authority of KKPAO. The model must incorporate the Six Building Blocks of a Health System proposed by the World Health Organization (t.ly/dtPR). This conceptual framework requires more than civic participation as stipulated by the Primary Health System Act of 2019. The second is to study and develop guidelines for promoting cooperation among partner agencies such as KKPAO and citizens in the province. The third is to formulate and propose policy recommendations for the KKPAO. Finally, it offers guidelines for adjusting the roles and responsibilities of the provincial health agencies under the MOPH in supporting and promoting the smooth transfer of HSPH to KKPAO. Data for this study were collected from primary and secondary sources related to health systems within Khon Kaen Province. The primary data were collected by interviewing the providers of health services, administrators, and the Director of the Public Health Division of KKPAO. In addition, focus group discussions were employed to solicit opinions and information about the transfer of SHPHs to KKPAO. Additional information and views were also gathered from organized public forums to maximize the richness and validity of data. The results from the analyses of data follow. All 248 SHPHs in KKP have been transferred from the MOPH to KKPAO. This remarkable success was accounted for by four factors: 1) clarity in the policy direction of the top manager; 2) trust and confidence of personnel of SHPHs and citizens in the management system of KKPAO; (3) personnel who transferred from the MOPH viewed this event as a window of opportunity for professional advancement; and (4) the personnel’s perception of the increased management and fiscal autonomy of SHPHs after the transfer. The transfer of SHPHs from the management responsibility of the MOPH to KKPAO has been in effect since January 2023. It was found that while the SHPHs were able to regularly provide and maintain quality primary care services in their areas, KKPO must view this as a window of opportunity to improve and streamline the health service provision system of SHPHs under its supervision. It is recommended that KKPAO inculcates a culture of services among the health workers and staff of SHPHs. Concerning this, the personnel of the SHPHs need to be trained and informed with the necessary information to 1) maximize the service responsibility of the personnel of the SHPHs; 2) provide recommendations for structural transformation and documentation operations; (3) create a progressive career path for personnel of transferred SHPHs; and (4) dispel any fear and apprehension about the regulative labyrinth of the required process of procurement, the arduous tasks of fiscal management, bookkeeping, coordination with KKPAO, development of performance metrics, establishing amicably inter-organizations relations, intra-organization reporting system, and self-development programs for the personnel. This study also found the indispensable functional roles of village health volunteers (VHVs) as a manifestation of citizen participation in health promotion. KKPAO must capitalize on its long and rich experiences in servicing its community. However, the VHVs we studied feared they would no longer be viewed as a part of the system. It is necessary, therefore, for KKPAO to build a clear understanding and perception among the VHVs that KKPAO recognizes the instrumental roles of the VHVs in health care promotion. This study also provides immediate and long-term policy recommendations for KKPAO. Immediately, the KKPAO should organize professional training courses to give orientation to create more understanding of KKPAO and to impart knowledge and improve the skills of the health workers of all SHPHs’ personnel regarding the management practices, authority, responsibilities, and organizational culture of the PAO. In addition, KKPAO must set up a liaison to provide management consultation for the workers of SHPHs. KKPAO must maintain and improve the skill of both permanent and short-term staff of SHPHs. As a long-term goal, it is recommended that KKPAO set up a specific public health unit to offer more specialized health services. This unit must also coordinate seamlessly between KKPAO and all SHPSs in the province. Moreover, this unit may have additional responsibilities such as developing performance metrics, networking, performance-based budgeting, promoting digital health services, and improving necessary skills to accommodate the new mission.