(CNN) Teen transgender reality star and activist Jazz Jennings says getting gender confirmation surgery months ago was "like a dream."

"This is a moment that I had always envisioned and just experiencing it was so surreal," Jennings told ABC's "Nightline" in an interview which aired Monday. "I was like, I can't believe this is happening."

Jennings is the subject of the TLC series "I Am Jazz," which has chronicled her life as a transgender girl. The series is set to return for a fifth season in January and viewers will see her surgery play out on air.

"This is really the last thing that will validate my identity as a woman," Jennings said during her interview. "There is nothing else after this."

The 18-year-old has said she realized early on that she was in the wrong body and reiterated that during her ABC interview.

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