1. A method to share healthcare information via a cloud-based clinical information system, comprising: receiving a selection from a first user to register a first healthcare entity with the cloud-based clinical information system as a first entity type, the first entity type one of a plurality of hierarchically organized entity types; registering the first healthcare entity with the cloud-based clinical information system, the first healthcare entity to have sharing and access rights to first healthcare information associated with the first healthcare entity based on the first healthcare entity being the first entity type; receiving an enrollment request to enroll the first healthcare entity with a second healthcare entity registered with the cloud-based clinical information system; storing a contractual agreement between the first healthcare entity and the second healthcare entity in the cloud-based clinical information system, the contractual agreement relating to second healthcare information associated with the second healthcare entity; enrolling the first healthcare entity with the second healthcare entity based on the contractual agreement and a selection of an access rule input by a second user associated with the second healthcare entity; and enabling the first healthcare entity to access the second healthcare information from the cloud-based clinical information system based on the access rule.