The cumulative number of participating units was 599, and the number of accredited units was 473 (average accreditation rate, 79.0%). The participating units consisted of clinics (58.6%), non-university hospitals (28.2%), and university hospitals (13.2%). Overall, 92.4% of university hospitals, 81.2% of clinics, and 68.0% of non-university hospitals were accredited. Over 5 years, new units were added annually to apply for accreditation, and the rate of previous participants applying for reaccreditation was high (77.7%). However, considering that the total number of member institutions of the KSN is 637, the number of units with valid accreditation as of 2020 was low (267 [41.9%]).