The invention proposes a switchable tappet (1) of a valve train of an internal combustion engine, said tappet comprising a hollow cylindrical housing (3) comprising a bottom (2), an inner element (5) being guided for relative axial displacement in a bore (4) of the housing (3), an at least indirect support for a gas exchange valve extending on a cam-distal front end (6) of the inner element (5), two diametrically opposing pistons as coupling elements (8) being arranged in a radial bore (7) of the inner element (5), which coupling elements (8), for effecting coupling [full valve lift], can be displaced partly beyond a parting surface (9) between the housing (3) and the inner element (5) into an entraining surface (12) of the housing (3) by the force of a compression spring (10a) clamped between inner front ends (10) of the coupling elements (8), wherein the entraining surface (12) is an direct constituent of a separate annular member (13) that is fixed in a cam-distal region of the bore (4) of the housing (3), wherein only one compression spring as a lost motion spring means (16) extends in a cylindrical hollow space (15) formed between an underside (14) of the bottom (2) of the housing (3) and a cam-side flat front end (14a) of the inner element (5), and wherein the inner element (5) is substantially disk-shaped and the parting surface (9) between the housing (3) and the inner element (5) does not comprise any vertical stop means.