To an unprecedented degree, this is the era of educational entrepreneurship. Dynamic new thinkers have waded into the world of K-12 education, founded influential organizations, and shattered familiar conventions. They have developed new models for delivering instruction and recruiting teachers and at the same time have applied old-fashioned practices with newly inspired fidelity. While their efforts constitute a still-minuscule portion of schooling, they are responsible for many of the most exciting developments in twenty-first century education. Is this a good thing? What does it mean, and what does it imply for school reform and policy? This paper discusses why entrepreneurship is important, how to make it work, differentiating reinvention of education from school choice, characteristics of the entrepreneurial presumption, and creating such an environment, including obstacles to be anticipated. (Contains 18 endnotes.)