Norman Spack is a pediatric endocrinologist at Boston's Children Hospital and the co-founder of the hospital's Gender Management Service clinic. Created in 2007, the clinic remains one of the few in the world that treats minors with hormone replacement therapy.

Spack began working with college-aged transgender patients professionally in 1985, but found that once patients had reached adulthood, it was extremely difficult to treat their sexually mature bodies using hormone therapy. When parents of transgender children began seeking him out through online support groups, Spack started to think about possible treatments for patients in their youth, before puberty has permanently changed their bodies. Since then Spack has spoken widely on pediatric hormone therapy and has campaigned for law reform in several states to protect transgender people against hate crimes and discrimination.