Overview
87,765 people (billing-related data April 2019–February 2026): names, birth dates, gender, insurer numbers, diagnoses, tests, drugs, procedures and clinical notes. No addresses, phones, My Number, bank or card data. No confirmed third-party leak, but the disk remains missing.
Timeline
- Occurred
- Discovered
- Disclosed
Organization response
Is searching on site, working with the PPC and police, and sending individual notices.
What you can do
Be wary of emails, SMS or calls impersonating the organisation; do not open links or attachments or enter passwords or card details. Change reused passwords on other services.
Sources
- 個人情報保存媒体の紛失に係るお詫びと対応について佐久総合病院 · 2026-11-09