Yes. There is the National Regulatory Agency for Private Health Insurances and Plans (Agência Nacional de Saúde Suplementar – ANS), that is linked to the Ministry of Health and is in charge to regulate the private health insurances and plans sector in Brazil  (National Regulatory Agency for Private Health Insurances and Plans, 2019a).

References:

National Regulatory Agency for Private Health Insurances and Plans. (2019a). Agência Nacional de Saúde Suplementar. https://www.gov.br/ans/pt-br