Despite repeated Soviet attacks, the narrow strip of land between Busse's 9th Army and Küstrin, dubbed the "Küstrin Corridor", was kept open. On 22 March a major Soviet effort to sever the corridor went into action. The Soviet plan consisted of an inner and outer encirclement. The inner encirclement succeeded quickly, and the corridor was cut. "Müncheberg" went into action on 22 March alongside XXXIX Panzer Corps. By 25 March the outer encirclement was completed, trapping several German units including a platoon from the "Müncheberg".