The purpose of this document is to describe the US ED growth model pilot program from its inception to the point at which the program was no longer a pilot and was opened up to all states. In addition, the paper is designed to help states in the process of planning to submit a growth model proposal. The information in this document is mostly public information from a variety of sources. By pulling the facts and figures together and organizing them as they are in this document, states should find the paper valuable, as it will provide a rich source of information about what types of growth models have been approved, features of growth models that have been important in the program, and the impact the growth models have had on state's AYP calculations. This document summarizes activities related to the growth pilot study from the start of the pilot in 2005 to the end of 2008. Though US ED continues to encourage states to submit growth-based accountability proposals, this document includes only events and approved models through December 2008. The document summarizes which states submitted proposals and which were approved. The paper describes the principles around the growth pilot study and the extent to which approved models meet those principles. Furthermore, it lists growth model features and the extent to which those features vary across approved models. Finally, it summarizes how including growth into AYP calculations has impacted the states with approved growth models and highlights next steps for growth-based accountability. This document is organized around eight sections: (1) US ED pilot study events; (2) Requirements and guidance for growth-based accountability models; (3) Three basic growth model types approved by US ED; (4) General descriptions of submitted models; (5) Features of 11 approved growth models; (6) Summary of approved growth models and how the growth models are used in adequate yearly progress (AYP) calculations; (7) Impact of growth models on schools and districts; and (8) Conclusions and next steps in growth-based accountability models. (Contains 5 tables and 2 footnotes.) [This paper was commissioned by the CCSSO Accountability Systems and Reporting State Collaborative.]