In 1984, Mr.Koshanov graduated from Karagandy Polytechnic Institute, and in 1999, from the Kazakh State Academy of Management. In 1988–1990, Yerlan Koshanov worked as an instructor in the Department of Working and Rural Youth; later, he worked as the head of the Department of Socio-Economic Problems of Youth of the Zhezkazgan Regional Committee of the Komsomol of Kazakhstan. In 1990–1995, Mr.Koshanov was the chief specialist, later the head of the department, then the deputy chairman and chairman of the Zhezkazgan Regional Committee of Foreign Economic Relations.

In 1995–1999, Yerlan Koshanov was elected to the Senate of the Parliament of the Republic of Kazakhstan. In 1999–2001, Mr.Koshanov served as a government representative to the Parliament of Kazakhstan. In 2001–2003, he held the position of Deputy Head of the Office of the Prime Minister of Kazakhstan as well as the Government Representative to the Parliament of Kazakhstan. In 2003–2006, Yerlan Koshanov served as a vice minister of transport and communication. Later in 2006–2007, he was Chairman of the Civil Aviation Committee of the Ministry of Transport and Communication. In 2007–2012, Mr.Koshanov held the position of Deputy Head of the Office of the Prime Minister as well as a Government Representative to the Parliament of Kazakhstan. In 2012–2017, he worked as the Head of the Office of the Prime Minister. From 2017–2019, Yerlan Koshanov worked as the Akim (executive head) of the Karagandy region. From 2019 to 2022, Mr.Koshanov served as the Head of the Executive Office of the President of Kazakhstan.

On February 1, 2022, he was elected as the Chairman of the Mazhilis of the Parliament of the Republic of Kazakhstan. On March 29, 2023, Yerlan Koshanov was re-elected as the Chairman of the Mazhilis of the Parliament. Mr.Koshanov holds several awards: the "Barys" I degree (2021), the "Parasat" (2013), the "Kurmet" (2007) orders, and jubilee medals. Mr. Koshanov fluently speaks Kazakh, Russian, and German.