On April 28, 1999, the final Mammography Quality Standards Act (MQSA) rule takes effect. On that date, the final regulations will replace the interim standards that have been in effect since October 1994. While the new guidelines are very similar to the interim guidelines, the final rule contains some important changes, particularly in the areas of personnel requirements and equipment standards. This article outlines modifications to the interim guidelines, with particular emphasis on requirements for radiologic technologists.