Background: Tumor, node, and metastasis staging in thyroid carcinoma is important for assessing prognosis. However, patients with stage III or IV disease have an overall survival rate of 90%. The change to 55 years of age as the cutoff will create stage migration and many patients will be downstaged. Methods: We reviewed our database of 3,650 patients to analyze the impact of the new American Joint Committee on Cancer staging system. There were 994 men (27%) and 2,656 women (73%). The median age was 46 years. Patients were staged using both 7th and 8th editions, with a cutoff of 55 years of age and new definitions of T3 and T4, and nodal staging. Results: Of 3,650 patients, 1,057 (29%) were downstaged. There were 104 (10%) who went from stage IV to I, 109 (10%) who went from stage IV to stage II, and 68 (6%) who went to stage III. There were 218 (21%) who went from stage III to I, 347 (33%) who went from stage III to stage II, and 211 (20%) who went from stage II to I. The overall disease-specific and relapse-free survival was analyzed and showed better stratification with the new staging system. Conclusion: The new staging system reflects more appropriately the biology of thyroid cancer and will have significant impact on the management of thyroid cancer.