This paper sets forth a framework for analysing fiscal sustainability in the Chilean economy. It starts by making an ex post calculation of indicators of vulnerability and fiscal sustainability, based on the estimation of a sustainable debt level, with public finances considered in stationary state. It then develops an ad hoc dynamic fiscal sustainability model for Chile’s public finances, which for the first time incorporates the dynamic of the Pension Reserve Fund (FRP) with its accumulation and disbursement rules, together with the cyclically adjusted balance policy. Lastly, the study simulates the path of the budgetary central government’s net debt up to 2025, using the projections made in the 2018 Public Finance Report, under a macroeconomic trend scenario and another adverse scenario, all framed by the cyclically adjusted balance rule.