All published guidelines on the use of radioactive iodine for the treatment of well-differentiated thyroid cancer agree that an individualized assessment of the risk of cancer-related mortality and of disease recurrence should direct the decision of whether radioiodine treatment is needed and how much to administer. At the author’s institution, they mostly follow the American Thyroid Association’s risk stratification system, with the addition of a category of very-low-risk patients that do not receive radioactive iodine.