Performance-based accountability (PBA) policies are increasingly adopted in a wide range of education systems in order to reform school governance and to improve students’ results and schools’ performance. Countries around the world have been implementing national large-scale assessments to make school actors more accountable and responsible for students’ results. This policy model has been generalized in countries with diferent administrative traditions, including those with a short tradition in New Public Management. This is the case in Spain, where PBA has been adopted unevenly in diferent regions, with Madrid being one of the earliest adopters. In recent decades, Madrid has developed a model that combines administrative test-based accountability with a system of broad parental school choice, which also facilitates the activation of market forms of accountability. However, the combination and interaction between market and administrative forms of accountability is understudied. This paper adopts a policy enactment perspective to analyze, through a case study approach, the interaction of administrative and market forms of accountability and its enactment at the school level. The case study is based on a set of 41 semi-structured interviews with teachers, principals, and school inspectors in a sample of eight schools in Madrid, combined with document analysis of school educational projects and improvement plans. The evidence suggests that administrative and market forms of accountability tend to generate dynamics of interdependence, resulting in increasing external pressures which schools tend to address with superfcial responses, including teaching to the test, or second-order competition between schools.