This paper focuses on the role of the private sector (including for-profit and non-profit organizations) in achieving Universal Health Coverage (UHC). It examines their involvement in the management, service delivery, resource investment and financing of primary health care (PHC) within the sustainable development goals (SDGs). The study covers a review of health systems, emphasizing the influence of private institutions on public health, and evaluates how private sector experiences contribute to system functions and progress towards UHC. The findings indicate the crucial role of the private sector in global health systems, notably expanded in several countries. Private actors are essential to improve access and coverage, particularly in countries with low health indicators. The article highlights the importance of primary care physicians understanding these dynamics since their management is vital in implementing public policies for UHC.