Proactive government transparency has recently entered the spotlight. Examples of information made public at the initiative of the public body, without the need for filing a request, are: www.data.gov and www.recovery.gov. Transparency is an intrinsic value of democratic societies. In much of the literature an automatic link is assumed between transparency and increased accountability or trust. However, this link may not be as straightforward. Whether and how information is used to further public objectives also depends on the way information is incorporated into the complex communication chain of comprehension, action and response. Therefore, in this dissertation a communication approach was taken. The role of federal government communicators within the government transparency realm was studied in the USA and the Netherlands. More specifically, it was examined how the institutional (macro) and organizational (meso) embedding influences the way communicators value and implement proactive transparency (micro). A mixed method comparative case study consisting of process tracing, a web-based survey and semi-structured in-depth interviews showed that the institutional embedding in the USA can be characterized as a more rules-based approach while a principles-based approach prevails in the Netherlands. This study also showed that communicators working in an organization that supports proactive transparency provide more substantial information, use less spin and are more inclined to solicit feedback and participation from stakeholders. Finally, in both countries the majority of communicators valued proactive transparency highly and most communicators were actively involved in implementing proactive transparency. Communicators contributed to making information more findable, relevant and understandable for its users. At the same time some communicators indicated to sometimes leave out important details, give only part of the story or specifically highlight the positive elements in the information. Hence, communicators can play a role in both enhancing and constraining transparency. This study enhanced our understanding of proactive transparency and the value of communication. The project resulted in a conceptual framework for explaining similarities and differences in proactive transparency policy regimes from the perspective of the government communicator