Labor Insurance Act Article 12

In case an insured person rejoins the labor insurance scheme after separation from the coverage, his accumulated years of insurance coverage shall be recognized.The insured person retired after December 9, 1999, and had suspended over 2 years before 21 February, 1979, or suspended over 6 years before 5 February, 1988, his accumulated years of insurance coverage shall be recognized.The insured person had received old-age benefits, should claim the shortage payment according to the proceeding paragraph in two years after last amended on December 19, 2001.
中文原文 勞工保險條例第12條
被保險人退保後再參加保險時,其原有保險年資應予併計。
被保險人於八十八年十二月九日以後退職者,且於本條例六十八年二月二十一日修正前停保滿二年或七十七年二月五日修正前停保滿六年者,其停保前之保險年資應予併計。
前項被保險人已領取老年給付者,得於本條施行後二年內申請補發併計年資後老年給付之差額。

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