A new method is presented to obtain a balanced reduced model for non-minimal discrete systems without calculating the full-order balancing transformation, which tends to be ill-conditioned for the system that has very nearly uncontrollable or unobservable modes, The method is based on finding the eigenspaces associated with the large and small eigenvalues of the product WcWoof the controllability and observability gramians using the ordered Schur decomposition. The method utilizes the weakly coupled subsystem to find the reduced order model from which the balanced reduced model is obtained. The proposed method is illustrated by several examples