Background: Accountability is increasingly being demanded of public services and is a core aspect of most recent frameworks of health system strengthening. Community-based accountability is an increasingly used strategy, and was a core aspect of India's flagship National Rural Health Mission (NRHM; 2005-2014). Research on policy implementation has called for policy analysts to go beyond the superficial articulation of a particular policy intervention to study the underlying meaning this has for policy-makers and other actors of the implementation process and to the way in which problems sought to be addressed by the policy have been identified and 'problematised'. Methods: This research, focused on state level officials and health NGO leaders, explores the meanings attached to the concept of accountability among a number of key actors during the implementation of the NRHM in the south Indian state of Tamil Nadu. The overall research was guided by an interpretive approach to policy analysis and the problematisation lens. Through in-depth interviews we draw on the interviewees' perspectives on accountability. Results: The research identifies three distinct perspectives on accountability among the key actors involved in the implementation of the NRHM. One perspective views accountability as the achievement of pre-set targets, the other as efficiency in achieving these targets, and the final one as a transformative process that equalises power differentials between communities and the public health system. We also present the ways in which these differences in perspectives are associated with different programme designs. Conclusions: This research underlines the importance of going beyond the statements of policy to exploring the underlying beliefs and perspectives in order to more comprehensively understand the dynamics of policy implementation; it further points to the impacts of these perspectives on the design of initiatives in response to the policy. © 2019 The Author(s).