This study identifies participation outcomes of 118 secondary mathematics teachers in a MS Math program at a mid-sized university in the southern U.S. Grant funds supported cohorts of 30 inservice secondary mathematics teachers in taking one graduate mathematics course per semester. Data sources included demographics, teaching observations, and employment records. Mixed methods findings included implications of four participation patterns: (1) transition to teacher leadership, (2) developing competency in mathematical knowledge, (3) sporadic progress, and (4) plateauing at the culminating master’s project.