Thanks for your question.
As many of the other plastic surgeons have pointed out. Very rarely does anyone *need* a labiaplasty (though I have had several patients treated in my San Francisco area practice who have had significant labial tears from childbirth or other surgeries who had insurance covered labiaplasty).
More commonly labiaplasty is for cosmetic reasons though we commonly have patients describe pain during sex or sitting who have had significant improvement.
Asymmetry of the labia minora can also cause self image issues that some women may wish to seek surgery to improve.
For the vast majority of women this can be considered a cosmetic procedure. Find a board certified plastic surgeon to discuss your concerns and needs.
I hope this helps.