This article analyses the privatization processes that have been implemented in the health systems of Argentina, Brazil, Chile and Colombia. It describes and characterizes the participation of the public and private components of each of these systems, and analyses the politics of the public policies involved in these privatization processes. The results reveal the presence of multiple public-private relationships that adopted different forms over time. The article also analyses some of the responses provided and the challenges faced by the health systems during the coronavirus disease (COVID-19) pandemic, along with the role played by private entities in particular. This analysis aims to examine the trajectories of the studied policies and to identify their limitations as well as potentialities for reversing privatization processes.