Social impact design -- one term that refers to the practice of design for the public good, especially in disadvantaged communities -- has attracted powerful interest in recent years. Increasingly, both practicing designers and students are seeking opportunities in this burgeoning discipline. But are the professional and academic structures in place to support them? And how might such structures be improved? On February 27, 2012, the "Social Impact Design Summit" was convened at The Rockefeller Foundation headquarters in New York to address the challenges and opportunities within the field today. Organized by the Smithsonian's Cooper-Hewitt, National Design Museum, with the National Endowment for the Arts and The Lemelson Foundation, the one-day event brought together 34 leaders of social impact design and a dozen representatives of foundations that support social programs. The summit participants -- who represented both nonprofit and for-profit organizations, as well as academic programs, government agencies, and non-governmental organizations (NGOs) -- drew a picture of a professional area that has demonstrated many achievements and much promise. Stretching across several design disciplines -- including product design, graphic design, urban design, and architecture -- and far from formalized in many aspects of its practice, social impact design also possesses a number of gaps and faces a variety of challenges. Among the forces inhibiting social impact design today, summit participants singled out the lack of a clear understanding of what the term means. Greater clarity, they proposed, would lead to better-defined goals and would boost appreciation of the value of the field. Participants also pointed to a dearth of accepted standards and ethical guidelines that would help normalize the practice, as well as a lack of knowledge-sharing structures among social impact designers, especially those who work across design disciplines.