Health quasi-markets aim to introduce competition into the public sphere by separating functions in order to improve efficiency and quality. In different public-private mixes, according to the morphology of health systems, different regulations can govern insurance, financing, and provision of services. The objective is to link financing to productivity, coverage, performance, and accomplishment of goals. Specifying guarantees to provide services for determined beneficiaries implies the formation of a purchase function based on strategic criteria involves three financing decisions: which interventions will be purchased, how they will be purchased, and from which providers. Some health systems in the region have established a separation of functions and some initial finance mechanisms based on results that allow them to be considered developing quasi-markets. On the other hand, some of them have introduced guarantees for various health services. Although such guarantees in all cases aim to improve equity in the level of health enjoyed by the population, they have very different repercussions in terms of the general organization of the related health systems depending on the level of development and the characteristics of the health coverage that the population already has. This study considers in the first place the introduction of health benefits guarantees in quite underdeveloped health systems, analyzing with more detail the case of Guatemala and briefly, Bolivia. Afterwards, a thorough analysis of Chile is done, showing how the health guarantees imply a partial overcome of the fundamental duality of the health system. Finally is considered the recent experience of the popular health insurance in Mexico, whose health insurance system is highly segmented. As we shall see in all the experiences, both the decentralization process and the specific public-private mix play an important role in the organisation of the health guarantees.