I didn't know you can do it, but it seems you can, so I thought I would share it here in case there are others who also didn't know. I got horribly sick on a long flight to Japan with a transit in Korea, and ended up in a clinic at Seoul airport. When I got back went with my wife to City Hall and much to our surprise found that such expenses can indeed be claimed back. In order to do so however the doctor at the hospital or clinic where the treatment occurs needs to fill in the appropriate paperwork. For this reason I wasn't able to claim back my expenses this time, but I've taken a copy of the paperwork and will carry it with me whenever I travel abroad. The guy at City Hall told me that I should submit the paperwork to him, and he will paper-push it to another department where the final decision will be made as to whether the money will be refunded and to what degree. He even mentioned the system applies not only for emergency treatment but also for scheduled operations, although he advised against this claiming it would be a long drawn out process. Has anyone had any experience of successfully claiming back under the Japanese National Health System any expenses incurred abroad?