Under the i3 scale-up grant, TFA planned to grow its corps by 80 percent and it aimed for a majority of its teachers to be rated as “highly effective” by the 2014–2015 school year. The implementation study, which examined TFA’s scale-up efforts during the first two years of the grant, included two components: (1) an analysis of whether TFA was able to meet its scale-up goals during the early years of the grant and (2) an analysis of whether it maintained fidelity to key aspects of its program model as it scaled program activities. The study found that TFA made notable progress in attaining its goals during the first two years of the scale-up, expanding the size of its corps by 25 percent, although it fell short of its annual targets for increasing the number of teachers in the program and teacher effectiveness. As it scaled its program, TFA generally maintained fidelity to its core program model, with some small changes taking place to its pre-service training program.