The modular LED retrofit lamp system includes a high-power LED light engine, together with an integrated optics mount, an integrated yet serviceable LED dimmable driver, and a point of attachment on the center area of the engine for mounting the LED engine. Different mounts for the engine can include, but are not limited to, PAR56, PAR46, PAR64, PAR38, Mini Candelabra, Intermediate Screw Base, Mogul Screwbase, and Fresnel-based Theatrical Fixtures. One LED light engine can replace a wide range of tungsten lamps ranging up to 500 watt equivalents in output performance, as well as dimming performance. Additional brackets and lamp sockets easily retrofit into an existing lighting fixture, while dimming capabilities are retained.