On January 1, the eighth and latest edition of the American Joint Committee on Cancer (AJCC)’s Melanoma Staging System officially went into effect. This highly anticipated periodic updating of the staging guidelines has considerable implications for communication among doctors and patients, selection of treatments and eligibility criteria for clinical trials. We are therefore very grateful to Drs. Balch and Gershenwald, who have been primary developers and authors of the guidelines, and their coauthors, Drs. Keung and Halpern, for updating us in this issue of The Melanoma Letter. Together, they have prepared a synopsis of the considerable changes in the guidelines and explained the motivations for those changes. They have also presented examples exploring the implications for therapy, with an emphasis on surgical management of regional disease.