A brace for a carpometacarpal joint of a thumb includes a body made of an elastomeric material. The body includes a wrist strap configured to surround a wrist, a dorsal projection extending from the wrist strap, a first palmar strap extending between a proximal end connected to the wrist strap and a distal end configured to removably attach to the dorsal projection, and a second palmar strap extending between a proximal end connected to the wrist strap and a distal end configured to removably attach to the dorsal projection. The brace also includes a heat-moldable insert positioned within the body. The heat-moldable insert is configured so as to be positioned over a CMC joint of the thumb.