A connection module for mounting on a busbar module or several busbar modules extending in a longitudinal direction includes: a housing, a rear side of which is mounted or mountable on the busbar module or busbar modules; a crossbar, movable on a first longitudinal side of the rear side of the housing transversely to the longitudinal direction, so as to provide a positive-locking connection of the connection module to the busbar module or the busbar modules in a mounted position of the connection module; and a latching profile on a second longitudinal side, opposite the first longitudinal side, of the rear side of the housing, the latching profile providing a positive-locking connection of the connection module to the busbar module or the busbar modules in the mounted position.