On 8 June 1940, the special municipality of Sibuyan was established through the passage of Commonwealth Act No. 581, sponsored by Congressman Leonardo Festin. Magdiwang was abolished and was annexed to the new municipality with its seat at Cajidiocan town proper. The special municipality of Sibuyan was abolished through the passage of Republic Act No. 38, which was authored by Congressman Modesto Formelleza and took effect on 1 October 1946, when President Manuel Roxas signed the Republic Act no. 38, restoring Magdiwang as a municipality.