The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders contains significant changes related to the diagnosis of gambling problems. These changes include the renaming of the disorder from pathological gambling to gambling disorder, reclassification of gambling disorder from an impulse control disorder to an addictive disorder, removal of the illegal acts criterion, lowering diagnostic threshold to endorsement of four criteria, and recognizing that the course of the disorder is no longer chronic for all diagnosed. This paper reviews the rationale and research support for these changes. Implications of the new revisions for both research and clinical practice are reviewed, including a discussion about future directions for research efforts.