Since established by an Appropriations Act in 2006, the Teacher Incentive Fund (TIF) competitive grant program in the U.S. Department of Education (USDE) has supported human capital strategies "to ensure that students attending high-poverty schools have better access to effective teachers and principals, especially in hard-to-staff subject areas" such as science and math. Responding to the national agenda to improve STEM education, in 2012, the fourth cohort of the Teacher Incentive Fund federal grant competition (TIF4) included special consideration for projects designed to improve STEM education by identifying, developing, and utilizing master teachers as leaders of broader improvements (OESE, 2012a). A human capital approach to strengthening STEM education addressed the TIF4 project schools' need for high-quality supports for student learning, and the systemic challenges to teacher retention, development, and recruitment in hard-to-staff subjects. The previous report in this series provided a descriptive overview of activities and interventions unique to the TIF4 project schools, setting the context for a meaningful discussion of programmatic impact. This analysis addresses student outcomes for State of Texas Assessments of Academic Readiness (STAAR) Mathematics (grades three through eight) and STAAR Science (grades five and eight), during the grant period of 2012-2013 to 2016-2017. On the whole, this report suggests that the complex programmatic aspects of the TIF4 program produced substantive and reproducible results for student achievement through human capital strategies. [For the first and third reports in this series, see ED603678 and ED603681, respectively.]