He was a member of the Investigating Committee for Preparatory Work for Independence (BPUPK), the organization which drafted the Constitution of Indonesia.

There, he was a part of the Panitia Sembilan (committee of nine), which would formulate the Jakarta Charter, the precursor of the Constitution of Indonesia.

He lay in state in the Pancasila room at the Ministry of Foreign Affairs and was then buried in the Kalibata Heroes' Cemetery.

[2] He then attended the Hogere burgerschool (HBS), the Dutch secondary school, in Batavia (now Jakarta), where he met and became friends with Arnold Mononutu (also from Minahasa) and Achmad Subardjo.

[11] Maramis was appointed to the Investigating Committee for Preparatory Work for Independence or Badan Penyelidik Usaha Persiapan Kemerdekaan (BPUPK) which was established on 1 March 1945.

This committee formulated a constitutional preamble that sought to capture the main values of the ideological principles called Pancasila that was outlined by Sukarno in his speech on 1 June 1945.

[13] He would later be asked by President Suharto in 1976 to be part of a committee to provide an interpretation of Pancasila as its meaning was thought to have deviated at the time.

As Minister of Finance, Maramis was instrumental in the development and printing of the first Indonesian currency notes or Oeang Republik Indonesia (ORI).

Between 1950 and 1960, Maramis represented Indonesia as ambassador to four countries: Finland, the Philippines, the Soviet Union, and West Germany.

Because his supervisory duties kept him abroad, he was included in the delegation of the Republic of Indonesia as an advisor to the Dutch–Indonesian Round Table Conference that took place in The Hague.

[26][27] In early 1956, Maramis returned to Jakarta and served as Head of the Asia/Pacific Directorate at the Indonesian Ministry of Foreign Affairs.

[30] After completing his service as ambassador to the Soviet Union and Finland, Maramis and his family settled in Switzerland.

Maramis died on 31 July 1977 at Gatot Soebroto Army Hospital, just 13 months after returning to Indonesia.

[35] He lay in state in the Pancasila room at the Ministry of Foreign Affairs and was then buried in the Kalibata Heroes' Cemetery.

[36] Maramis was married to Elizabeth Marie Diena Veldhoedt, the daughter of a Dutch father and Balinese mother.