Teach For America (TFA) and the Teaching Fellows programs are an important and growing source of teachers of hard-to-staff subjects in high-poverty schools, but comprehensive evidence of their effectiveness has been limited. This report presents findings from the first large-scale random assignment study of secondary math teachers from these programs. The study separately examined the effectiveness of TFA and Teaching Fellows teachers, comparing secondary math teachers from each program with other secondary math teachers teaching the same math courses in the same schools. The study focused on secondary math because this is a subject in which schools face particular staffing difficulties. The study had two main findings, one for each program studied: (1) TFA teachers were more effective than the teachers with whom they were compared. On average, students assigned to TFA teachers scored 0.07 standard deviations higher on end-of-year math assessments than students assigned to comparison teachers, a statistically significant difference. This impact is equivalent to an additional 2.6 months of school for the average student nationwide. (2) Teaching Fellows were neither more nor less effective than the teachers with whom they were compared. On average, students of Teaching Fellows and students of comparison teachers had similar scores on end-of-year math assessments. By providing rigorous evidence on the effectiveness of secondary math teachers from TFA and the Teaching Fellows programs, the study can shed light on potential approaches for improving teacher effectiveness in hard-to-staff schools and subjects. The study findings can provide guidance to school principals faced with the choice of hiring teachers who have entered the profession via different routes to certification. The findings can also aid policymakers and funders of teacher preparation programs by providing information on the effectiveness of teachers from various routes to certification that use different methods to identify, attract, train, and support their teachers. (Contains 2 figures and 3 footnotes.) [For the full report, see ED544171.]