Nowadays, the role of patients in the healthcare domain is extending beyond being passive healthcare recipients to becoming "makers and shapers" of healthcare services. In the healthcare service ecosystem, Online Health Communities (OHCs) foster co-creation among the different actors. Over the last five years, a number of articles that focus on value co-creation in the healthcare services have surfaced that highlight the significance of the interactions and engagements between the healthcare ecosystem levels. Accordingly, this paper aims to conduct a systematic review of the literature focusing on the role of OHCs as facilitators of value co-creation in the healthcare service ecosystem. A systematic review of the literature was conducted with articles published between 2013 and 2018. Thematic analysis revealed three key themes including "value is ubiquitous", "online resources connectivism", and "informational and emotional support". This paper provides a structured overview of the current literature and identifies opportunities for future research.