Magnolia sororum is native to the mountains of Costa Rica and western Panama, including the
Cordillera Central and
Cordillera de Talamanca. The species' estimated extent of occurrence (EOO) is around 20,000 km2. A population was reported in
Bosawas Biosphere Reserve in northern Nicaragua. If confirmed, this population would extend the species' EOO to around 60,000 km2. It is found in mature humid
upper montane forests from 2,300 to 3,200 meters elevation. In Panama its range extends into lower montane forests. ==Subspecies==