One of the following: Medical Staff organisation An organised group of physicians, usually from one hospital, into an entity able to contract with others for the provision of services, or Management (or Medical) Services Organization. An entity formed by, for example, a hospital, a group of physicians or an independent entity, to provide business-related services such as marketing and data collection to a grouping of providers like an IPA, PHO or CWW. This second definition is becoming the almost exclusive usage. See Management Services organisation or Medical Services Organization.