Enforcement Rules of the National Health Insurance Act Article 32

The term “missing” referred to in Article 13 of the Act means missing, untraceable, or persons in search that are registered in police agencies or immigration agencies.The beneficiary may cease to be covered from the date of occurrence of the disaster which caused his/her being missing.
中文原文 全民健康保險法施行細則第32條
本法第十三條所稱失蹤,指經警察機關或移民主管機關受理登記為失蹤、行方不明或查尋之人口。
保險對象因遭遇災難失蹤,得自該災難發生之日退保。

English translation for reference only; the Chinese text prevails. Not legal advice.