Gender-affirming mastectomy is a type of surgery that removes breast tissue, tightens the skin, and can adjust nipple placement to provide the desired results of a more masculine-looking chest. Mastectomies started as a way for surgeons to remove breast cancer and tumors from the breast tissue. However, as of 2022, surgeons also use the procedure as a means of gender-affirming surgery for transgender and non-binary, hereafter TNB, individuals. If a person identifies as transgender, their gender identity differs from the sex they were assigned at birth and the gender they were most likely raised as, which can produce gender dysphoria, a condition that can last a lifetime. Non-binary individuals may have a similar experience, but they identify outside of or between the identifiers of man and woman. Gender-affirming mastectomy, sometimes called top surgery, improves the quality of life for people who seek the appearance of a masculine chest to both better integrate themselves into society and lessen the mental and emotional burden of gender dysphoria.