OBJECTIVES: To describe the instrument NIP (Notification of Preliminary Investigation) and it’s role on solving conflicts related to the obligatory coverage access, between health plans and patients.  METHODS: A critical analysis of the rule that created NIP (Regulatory Resolution nº 226/2010), established by The Federal Regulatory Agency for Private Health Insurance and Plans (ANS), was done to characterize the tool.  RESULTS: The Notification of Preliminary Investigation (NIP) consists of a communication time to mediate the relationship between consumers and providers of health plans in cases of unauthorized procedures by the provider. NIP is an electronic process to solve the conflicts before a process that can lead to the punishment of the health plan provider. A contact is previously made to notify the health plan provider about the problem and it has five business days to answer it. This way, the health plan provider has the opportunity to solve the question without punishment and the beneficiaries can have a faster access to the procedure prescribed by the doctors. If the procedure doesn’t have coverage according to the supplementary health rules (it is not listed on ANS Medical List of Procedures), the demand is filed. If the provider’s answer is not enough to conclude the question, it’s sent to the Inspection Department to a more detailed analysis before being finished. CONCLUSIONS: The NIP is a mediation instrument that can help ANS to solve the problems between beneficiaries and health plan providers, giving a fast answer to both interested actors of the process. It can be positive because sometimes the questions are solved without the provider punishment and the beneficiaries’ injury. The conflict mediation by NIP can contribute to the change in the entities attitude and culture and can also promotes the interaction and the active participation of the actors involved.