Radioiodine therapy has been used for many years to treat thyroid disease. The use of 131I sodium iodide in mCi dosages poses potential hazards to health care personnel, family or close friends of the patient, and the general public. The US Nuclear Regulatory Commission (NRC) is charged with protection of health and safety from various radioactive materials including 131I. The NRC accomplishes its mission through regulations and license conditions placed on the authorized use of radioiodine. Current regulations limit annual whole body dose of 1 mSv (100 mrem) for members of the public and 50 mSv (5,000 mrem) for radiation workers. To protect patients from dispensing errors, the NRC promulgated regulations on possession use, calibration, and check of dose calibrators and outlined procedures to follow if an error is made. This paper discusses these requirements, methods for meeting them, the process used by the NRC to change its regulations, a proposed rule on release of patients who contain therapeutic radionuclides, and some commentary from the National Council on Radiation Protection and Measurements that medical licensees may find useful.