ELA, Volume 13, pp. 405-418, December 2005, abstract. Schur Complements and Banachiewicz-Schur Forms Yongge Tian and Yoshio Takane Through the matrix rank method, this paper gives necessary and sufficient conditions for a partitioned matrix to have generalized inverses with Banachiewicz-Schur forms. In addition, this paper investigates the idempotency of generalized Schur complements in a partitioned idempotent matrix.