This paper conceptualizes knowledge in the IS literature on governing innovation in platform ecosystems using boundary resources. Platform innovation arises when platform owners realize the need to expand the functionalities and invite external actors with specialized knowledge to do so. We conduct a literature review to identify the relevant concepts on governing innovation in platform ecosystems in IS and adapt them to the specific settings of the eHealth context. As most relevant concepts, we identify: 1) boundary resources as governance mechanisms: openness vs. control; 2) co-creating platform innovation across heterogeneous actors: accommodation vs. resistance; and 3) platform innovation within the underlying architecture: stability vs. flexibility. We then derive areas that should be prone to further research in eHealth, defined as: 1) patient data as a resource for eHealth platform innovation; 2) the role of institutions in eHealth platform innovation; and 3) innovating within platform-oriented eHealth information infrastructures. This paper contributes by expanding the understanding of the current state of knowledge in IS on governing innovation in platform ecosystems and provides basis for further research adapted to the eHealth context settings.