National Health Insurance Act Article 69

The contracted medical care institutions shall check the qualifications of the beneficiary when they visit, matching them to the information on the NHI Card. The Insurer may refuse to pay medical expenses for those who have not been checked and shall seek reimbursement if the medical expenses have been paid. This is inapplicable to matters not attributable to contracted medical care institutions.
中文原文 全民健康保險法第69條
保險醫事服務機構應於保險對象就醫時,查核其健保卡;未經查核者,保險人得不予支付醫療費用;已領取醫療費用者,保險人應予追還。
但不可歸責於保險醫事服務機構者,不在此限。

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