In 1947, Seattle's Virginia Mason Clinic and Group Health Cooperative begin collaborating. This is the year, two years after its founding, that Group Health begins offering medical services.
The King County Medical Society (local branch of the American Medical Society) opposes both Virginia Mason and Group Health for the "sin" of group practice (as opposed to solo fee-for-service practice). As a result most area hospitals -- Renton Hospital, Swedish Hospital, and Seattle General among others -- refuse staff privileges and assistance to Group Health physicians. Virginia Mason, which also offers a group practice, maintains an "open-door policy for Group Health physicians" and both begin to share resources for collaborative services such as radiation therapy and pathology.