OBJECTIVES: To describe the main actions promoted by the The Federal Regulatory Agency for Private Health Insurance and Plans (ANS) to regulate the access of private health plans beneficiaries to an adequate and an integral assistance. METHODS: A retrospective analysis of data about coverage in health plans since ANS creation (1999) was done to identify the main actions promoted by the agency in this area. It included the set of rules published and ANS periodic publications. RESULTS: A very important identified mechanism that ANS employs for regulating the users access to a full assistance is the elaboration of a list of medical procedures. This list constitutes the minimum obligatory coverage for all plans. It is periodically reviewed and incorporations and/or exclusions are made according to some precepts like: clinical evidence, epidemiological relevance, among others. The guidelines implementation is another important instrument identified in this study to the improvement of private health assistance. ANS established a collaboration term with the Brazilian Medical Association (AMB) to develop guidelines, to spread and to monitor their implementation. CONCLUSIONS: The actions presented are the main one promoted by ANS to regulate the access to an adequate and an integral assistance. They can also improve the sector efficiency along with the rational use of techniques and medical technologies. The instruments discussed will be a guide to upgrade the health plans management and their efficiency. The patients will have safer end more effective treatments and ANS keeps the balance and promotion of health in private health with a new model.