National Pension Act Article 21

If the insured person qualifies with the mentally/physically disability pension payment, mentally/physically disability basic guaranteed pension payment, old age pension payment, old age basic guaranteed pension payment, and surviving family pension payment at the same time, he or she is entitled to request one payment only.
中文原文 國民年金法第21條
被保險人符合身心障礙年金給付、身心障礙基本保證年金、老年年金給付、老年基本保證年金及遺屬年金給付條件時,僅得擇一請領。

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