In 1996 and 2011, the American Society of Hematology (ASH) supported efforts to create guidelines for the diagnosis and management of patients with immune thrombocytopenia (ITP). These guidelines used different approaches to arrive at recommendations for testing and treatment. Despite differences in methodology, in both cases there was a paucity of randomized trials to inform recommendations. As data on the diagnosis and management of ITP expands, the ASH Committee on Quality is dedicated to maintaining updated guidelines representing recent evidence and guideline methodology. Here, we will review the updated ASH guidelines on ITP with a focus on recommendations with new understanding and future research to close knowledge gaps.