Hovhannes Ter-Mikaelyan graduated from Medical Department of Kharkov University in 1898 and worked as an intern at University hospital till 1903.
In 1914, he joined the army and was appointed the assistant to the chief doctor of Yerevan military hospital.
In 1917, Ter-Mikaelyan was appointed the doctor of brigade and occupied the position until March 1, 1919.
From June 1 to August 1, 1918 he was a member of Yerevan National Assembly leadership.
By the end of 1920, he frequently took over the responsibilities of the Minister.