The present invention relates to a coupling device for a valve-actuating device for actuating at least one valve of a reciprocating machine having variable valve lift, in particular for a valve-actuating device of a reciprocating internal combustion engine, to a valve-actuating device and to a reciprocating machine, the coupling device comprising a first coupling element, a second coupling element and a blocking means. The first coupling element and the second coupling element can be displaced relative to one another at least within defined boundaries along a first axis, it being possible for the blocking means to block the relative displacement of the two coupling elements with respect to one another along the first axis at least in a first direction. The blocking means comprises a blocking element, which can be rotated about the first axis in the circumferential direction at least in a defined region, the relative displacement of the two coupling elements along the first axis being blocked at least in the first direction if the blocking element is in a blocking position.