Enforcement Rules of the National Health Insurance Act Article 35

In the case that a beneficiary meets one of the conditions in the preceding Article, the group insurance applicant shall complete and submit one copy of the Insurance Withdraw Coverage Application Form to the Insurer for termination of coverage within three days, and at the same time provide a copy to the beneficiary.
中文原文 全民健康保險法施行細則第35條
保險對象有前條所定情形之一者,投保單位應於三日內填具保險對象退保申報表,送交保險人辦理退保手續,同時提供予保險對象。

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