Zack Hogle woke up feeling groggy, sore and — at last — whole. He had just undergone more than 14 hours of surgery, but he was elated. “When I looked down at my body, I couldn’t stop crying,” he says. “I finally felt like myself.”

The surgery was the last step in what had been a lifelong journey. Growing up in a small town in Western Massachusetts, Zack, now 24, says he always knew he felt different. “I hated my body,” he remembers. “I thought, ‘I’m not the same as other kids and this isn’t okay.’” It wasn’t until he was in high school that he learned the word transgender and what that meant. The realization was a turning point. …