In 2010-2011, the School District of Philadelphia (the District) launched its Renaissance Schools Initiative, a program designed to dramatically improve student achievement in the District's lowest performing schools. Some schools became Promise Academies, based on the federal turnaround model, and remained District-operated neighborhood schools. Other schools became Renaissance Charters, based on the federal restart model, and shifted management to external charter providers while remaining neighborhood schools. The District has added new Renaissance Schools each year from 2010-2011 through 2013-2014 and, to date, converted 20 schools to Renaissance Charters and 15 to Promise Academies. Three of those 15 Promise Academies have since closed. Early research showed improved student outcomes in Cohort One Promise Academies initially (Gold, Norton, Good, & Levin, 2012), but after three years, the majority of Promise Academies had not achieved rapid or dramatic increases in student achievement (Wolford, Stratos, & Reitano, 2013). Meanwhile, Renaissance Charters, which were showing improvements on par with Promise Academies after Year One, demonstrated rapid growth in student achievement in more than half of the schools after Year Three (Gold et al., 2012; Wolford et al., 2013). This article explores the implementation of the Promise Academy model over the first four years of the initiative and, in particular, examines why the model has floundered compared to the relative success of the Renaissance Charters.