Some people pursuing a doctorate in mathematics education are interested in specializing in a specific area within mathematics education. In addition, people considering postdoctoral appointments often choose institutions that have niches or specializations aligned with their long-term career goals. These specialty areas are typically the result of the foci of specific faculty members who are active in research and scholarship and have gained broad recognition for their work. This brief report offers information about specific areas of specialization within doctoral programs in mathematics education in the United States that are recognized by peer faculty at other doctoral institutions.