A surgical instrument includes an elongated shaft module and a handle module selectively separable from one another. The elongated shaft module includes an elongated shaft member and a pair of jaw members supported at a distal end of the elongated shaft member, at least one of the jaw members moveable relative to the other jaw member between open and closed positions. The handle module includes a housing including an opening extending longitudinally therethrough. The opening is dimensioned to permit passage of the pair of jaw members in the closed position. The handle module also includes a movable handle movable relative to the housing to move the pair of jaw members between open and closed positions, and a lock to secure the elongated shaft module in place within the housing.