Mr. Efraim Čosić was born in Breza, in 1957, where he finished both the primary school and the High School. On 30 March 1982, Mr. Čosić graduated from the Faculty of Law in Sarajevo. He worked in the field of economy (in the RO “Viteks”, or the “Breteks” Socially-Owned Company Breza), from 26 April 1982 through the summer 1992 as the Head of Department for General, Legal and Personnel Issues. From early 1999 through 22 March 2004, Mr. Čosić worked with the administrative body of the Municipality Novi grad Sarajevo as a Senior Legal Officer, and subsequently as an Expert Advisor. Mr. Čosić passed the bar exam on 18 June 1999 in Sarajevo. In February 2004, he was appointed Judge of the Basic Court in Sokolac, assumed his duty on 22 March 2004 and worked with the referenced Court through the end of 2010, when he was appointed additional judge to the Cantonal Court in Sarajevo. He assumed his duty on 4 January 2011 and worked in the Cantonal Court Sarajevo until 1 May 2016.

On 13 April 2016, Mr. Čosić was appointed Judge of the Court of Bosnia and Herzegovina and assumed his position on 1 May 2016.