Japan is undertaking medical system reforms in order to suppress the ballooning national medical expenses of the aging society. Medical computerization is one of the focal issues for this. The government has stated a plan to mandate the online billing of medical service fees for all medical institutions. The prevalence of electronic medical records (EMR), which has been delayed due to unsophisticated information technology (IT) and the limited IT literacy of elderly medical staff in general, should be promoted. Without the prevalence of EMR, several social innovations, the regional coordinated medical service, and the future National Health Record service etc., will not become reality. The author advocates inducing newcomers to innovate business models by means of deregulations, so as to promote more investment in the medical information market from the business sector, and to accelerate the build-up of regional medical information networks based on networked EMR systems.