Hospital, as one of the most complex public sectors that currently exist, has problems with structuring and organizing its IT capabilities. The applications in hospital information system usually work independently, making clinical data spread heterogeneously in the system. Failure in IT implementation has increased due to the lack of integration and alignment with the organization goal. Enterprise architecture has been considered as a solution for such problems, but there is currently no standardized guidelines to tailor it for hospital. The existing approaches from researches do not provide two core requirements of hospital information system architecture: the capability to handle multiple branches and the exhaustive view of the whole topology, from business to technology architecture. This paper aims to define the suitable approach to build enterprise architecture for hospital information system by defining the architectural needs, analyzing the existing frameworks to fit the requirements, and tailoring the architecture as the proposed solution. The case study to support the research is conducted in one of the biggest hospital group in Indonesia, Permata Group Hospital.