Indigenous Peoples Status Act Article 6

To acquire indigenous status, the individual may apply to adopt or list in indigenous writing the traditional indigenous name, or adopt the surname of one of the indigenous parents; the application may be arranged in writing by the statutory representative during the period the child is a minor, and apply by personal preference after said child has reached legal age, not restricted by Items 1 and 4 of Article 1059, and Items 1 and 2 of Article 1078 of the Civil Code, or Item 2 of Article 1 of the Name Act.Other than birth registration, application to acquire indigenous status as provided in the preceding paragraph is limited to once per minor period and once after the child has reached legal age.Adopted children acquiring indigenous status via application as provided in Paragraph 1 may apply to the Household Registration Office as interested persons for the household registration record or the household certificate transcript of their birth parents as provided in Article 65 of the Household Registration Act.
中文原文 原住民身分法第6條
為取得原住民身分,當事人得申請取用或以原住民族文字並列原住民族傳統名字,或從具原住民身分之父或母之姓;當事人未成年時,由法定代理人以書面約定申請,成年後,依個人意願申請,不受民法第一千零五十九條第一項、第四項、第一千零七十八條第一項、第二項及姓名條例第一條第二項規定之限制。
依前項規定申請取得原住民身分,除出生登記外,未成年時及成年後各以一次為限。
養子女依第一項規定申請取得原住民身分者,得以利害關係人身分,依戶籍法第六十五條規定向戶政事務所申請本生父母之戶籍資料或戶籍謄本。

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