Online transparency for accountability assessment exercises reported in the literature rely solely on the analysis of public entities’ individual web sites, measuring the data disclosed and the way it is disclosed, and not taking into consideration the context in which these ‘target’ entities operate. This paper aims at identifying key contextual elements that may influence the way data is disclosed by public entities in their individual web sites, and therefore should be taken into consideration when designing the assessment models and exercises. The contextual elements identified were organized into an online transparency for accountability maturity model that may be used on its own to assess the overall level of sophistication of a country or region (‘context’), or it may be used in a stage-gate approach to define the appropriate type of entities assessment model. Researchers wanting to assess a set of ‘target’ entities should therefore begin by analyzing the context in which they operate (using the proposed maturity model) and then define their assessment model according to the recommendations proposed in this paper for the corresponding maturity level.