 He is an editor of the Journal of the American Mathematical Society and Geometry and Topology.He collaborated with Gang Tian in verifying Grigori Perelman's proof of the Poincaré conjecture.The Morgan–Tian team was one of three teams formed for this purpose; the other teams were those of Huai-Dong Cao and Xi-Ping Zhu, and Bruce Kleiner and John Lott.