An electromechanical camshaft phasing system comprising a first pinion gear mounted on the end of an engine camshaft and engaged by a worm gear mounted on a transverse shaft extending from and journalled by bearings in a phaser drive sprocket to cause the camshaft to rotate in response to the engine crankshaft. The first pinion gear is surrounded by a ring gear having a hub keyed to an armature or stator shaft of a motor mounted on the engine coaxially of the camshaft and first pinion gear. A second pinion gear mounted on the worm gear shaft engages the ring gear such that motor rotation of the ring gear about the first pinion gear causes rotation of the second pinion gear, worm gear, first pinion gear, and thus the camshaft with respect to the sprocket, thus varying the phase of the camshaft with respect to the crankshaft.