It is a type of closed-panel HMO (where patients can receive services only through a limited number of healthcare service providers) in which physicians are employees of the HMO. The physicians see patients in the HMO’s own facilities. In other words, Staff model is a type of HMO in which physicians who are employees of the HMO provide healthcare products and services under the plan. These contrast with the ‘independent practice association (IPA)’ HMO, in which independent physicians contract with the HMO.