The Costa Rican Social Security Fund (CCSS) is one of the public institutions that defined the country's path in the twentieth century. Based on values of responsibility, commitment, respect, courtesy, honesty, respect for people, its philosophical principles, ethical principles, mystique, commitment and excellence in the work of the institution's employees are pillars in the operation of this institution and in the social peace of Costa Rica. This paper reviews the philosophical framework, the structure of the institution's senior management, and shows how the insurance structure is conformed, whether it is health, pension or non-contributory. At the operational level, the reader will learn about the conformation, distribution, hierarchies, operation of the health services network, health facilities by levels of care, as well as the organization of care services at the first level known as the EBAIS. In addition, you will learn the principles of internal control that the institution must comply with given the internal control law applied to public institutions in Costa Rica.