Later, during the interwar period Blumentritt served as a company leader in the 3rd Thuringian Infantry Regiment No. 71 from 20 February 1919. After the military restrictions imposed by the Treaty of Versailles came into effect, he was briefly a member of the "Freikorps" (paramilitary organization) formed by the veterans of the 3rd Thuringian, before transferring back to the regular army with the 22nd "Reichswehr" Rifle Regiment on 1 October 1919. Then later he served as a staff officer in several positions, first as operations command officer from 1 April 1926 in the staff of the 6th Division. He was promoted to "major" in September, 1933, then worked as a lecturer and tactics instructor at the "Kriegsakademie" in 1935, and finally was promoted to "oberst" in October 1938. He eventually served as a staff officer under Wilhelm Ritter von Leeb, along with his friend Erich von Manstein.