Simina returned to Chuuk after graduating from college and worked for the Chuuk Public Defender's Office as an intern for four years. From 1988 to 1991, he was Directing Attorney for the Public Defender Office in Kosrae and Chuuk. He became a legislative counsel for the Chuuk State Legislature in 1991. He served as Attorney General for Chuuk from 1993 to 1997, and worked as a private practice lawyer for seven years after leaving office. Simina was elected as Chuuk's at-large representative to the 3rd constitutional convention in 2001. Simina was elected as
Governor of the
Chuuk State in 2005. Simina defeated Gillian N. Doone, the son of
Gideon Doone, in the 2009 election after it went to a runoff election. Johnson Elimo won the 2011 special election to succeed Simina after he was elected to the
Congress of the Federated States of Micronesia. Simina was elected to the congress in a 2011
by-election. He was reelected in the
2015 elections. On May 11, 2015, he was elected as the 6th Speaker of the congress. During his tenure in congress he was a member of the Education, External Affairs, and Transportation and Communications committee. He was the chair of the Judiciary and Governmental Operations committee. Congress elected Simina as
President of the Federated States of Micronesia on 11 May 2023. ==Personal life==