This study describes the firebrand spotting parameterization in the WRF-Fire model. The implementation of firebrand processes for generation, transport, burnout, landing, and ignition is described alongside idealized simulations configured for coupled and uncoupled feedback between fire and atmosphere. The implemented parameterization is then applied to assess its effect on a real-case simulation of the most costly fire in the state of Colorado, the Marshall Fire, in which spot fires played a significant role in spreading the fire through an urban area.