In 2014, the US Department of Education awarded the Maricopa County Education Service Agency an Investing in Innovation (i3) grant to fund the Engineering STEM Identity (ESI) project. The purpose of i3 is to expand the implementation of, and investment in, innovative educational practices. Accordingly, the goal of ESI is to address one of the most important challenges facing education: developing student interest and proficiency in the fields of Science, Technology, Engineering, and Mathematics (STEM). This grant was funded by Department of Education No. U411C30116-i3. As part of the evaluation of i3 funded projects, grantees must study and report on the degree to which a project is carried out as planned. This type of study provides researchers and practitioners a better understanding of how and why an intervention works, and the extent to which outcomes can be improved. Importantly, if it is found that the project was not implemented properly then it is not possible to clearly conclude that the project had an effect on the students' performance. The Fidelity of Implementation (FOI) document presents a conceptual and analytic framework for assessing the quality of the implementation of the ESI project. The conceptualization of the present FOI was completed October 1, 2014 after reviewing the ESI grant activities and selected quantitative ratings to be employed. The approved FOI approach assesses the implementation of three constructs: Construct 1: Curriculum and Instruction. Construct 2: Teacher Professional Development. Construct 3: Administrative Support of the principal or other administrative personnel. This present method of analyzing the Fidelity of Implementation of a major educational project was completed with the Maricopa County Education Service Agency (Arizona) Engineering STEM Identity Project. The reports provide evidence of meeting fidelity of implementation of their federal grant. An appendix displays the rating scales for the constructs of the Fidelity of Implementation Report.