Jharkhand Mukti Morcha (B), a political party in India 1980-1990. JMM(B) was formed when JMM leader Binod Behari Mahato, following the decision by the JMM to contest elections in alliance with Indian National Congress. Mahato returned to JMM in 1987, after the killing of JMM president Nirmal Mahato (allegedly with Congress activists). JMM(B) merged with JMM in January 1990.