An apparatus for retaining and releasing a pump down plug includes an outer housing having a recess and a shifting sleeve that contains the pump down plug and is disposed within the outer housing. The shifting sleeve is configured to slide within the outer housing. The apparatus also includes a retaining element configured to engage the pump down plug to retain the pump down plug, the retaining element being restrained from outward movement by the outer housing in a first position of the shifting sleeve, wherein sliding the shifting sleeve into a second position results in outward movement of the retaining element into the recess to release the pump down plug.