In 1919 as a member of Frontlines Bureau Farbman was in charge of the information and communication party department and a member of Orgbureau of the Communist Party of Ukraine. From January through March 1920 he acted as a secretary of the central committee in the absence of Stanislav Kosior. Later in 1920 Farbman moved to Moscow where he headed a city department of People's Education. He was a delegate at the 9th and 10th congresses of RSDLP(b). On December 18, 1927 Farbman was excluded from the Communist Party as a member of the United Opposition on a decision of the 15th Congress of the CPSU, but in 1932 he was reinstated. In 1930-35 Farbman worked as a deputy chief of the Trust Administration "Rudmetalltorg" (Metal-ore trade). In 1933 he was excluded from the party once again for Trotskyism and in 1935 he was arrested, receiving a life sentence. Farbman was freed only in 1956 and received an amnesty. He died in 1966.