The objective of this article is to analyze the relationship between the cost of assistance and the aging of the population assisted by a self-management plan, reflecting on the possibilities of facing the challenge arising from this combination of factors. This is a descriptive study from the period 1997 to 2016, carried out based on secondary data from the health plan operator under study, and another administrative bank of self-management operator of national scope. The elderly (over 60 years) increased by 55.5% during the study period. The so-called “very elderly” (over 80 years old), in turn, grew by 332.8%. The population over 60 years old corresponds to 25.7% of the total, being responsible for 68.8% of expenses. The vast majority of the population served (84.6%) is located in the state in Rio de Janeiro, which has the highest per capita health cost in the country. A relationship was found between the aging of the beneficiary population and the increase in expenses. It is imperative to invest in health promotion and disease prevention initiatives as a way of improving the quality of life and financial viability of the plan, in addition to defining a sub-system that delimits and disciplines access to the network and is accepted by the beneficiaries.