The Special Education Act Article 14

The enrollment age, grade placement, class location, instruction practice and duration of schooling of special education students shall be flexible to the extent to their special educational needs; procedures and details of practices including lowering or raising the enrollment age, shortening or extending duration of schooling, are all determined by the central competent authority. In case of any legal provisions, their regulations shall be followed.
中文原文 特殊教育法第14條
為因應特殊教育學生之教育需求,其入學年齡、年級安排、教育場所、實施方式及修業年限,應保持彈性;其提早或暫緩入學、縮短或延長修業年限及其他相關事項之辦法,由中央主管機關定之。
但法律另有規定者,從其規定。

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