A valvetrain includes a rocker arm assembly having a rocker arm and an electromagnetic latch assembly. A magnet of the latch assembly is housed within a chamber formed by the rocker arm. The chamber may be a retrofit hydraulic chamber. The magnet may be an electromagnet or a permanent magnet. A flux shifting bi-stable latch provides a sufficiently compact design. Isolation of the magnet within the rocker arm chamber may provide protection from metal particles carried by oil in an operating environment for the rocker arm assembly.