American Thyroid Association (ATA) guidelines for the management of thyroid nodules and differentiated thyroid cancer (DTC) were first published in 1996 and subsequently updated in 2006, 2009, and 2015. In 2025, the ATA released a revised version focusing exclusively on DTC and excluding thyroid nodules from its scope. In our previous review, we summarized the updates regarding preoperative evaluation, diagnosis, and surgical management of DTC. In this second part of the series, we aimed to compare the 2015 and 2025 ATA guidelines in terms of initial postoperative management. The main changes are evaluated at the level of recommendations, with a particular emphasis on recurrence risk stratification, postoperative risk-adapted surveillance, adjuvant radioactive iodine (RAI) use, postoperative imaging, and radiation safety. This review provides a comprehensive comparison of the 2015 and 2025 ATA guidelines, outlining the key changes in early postoperative management of DTC and highlighting their potential impact on individualized patient care.