Operating out of the University of California, Berkeley, Y-PLAN (Youth—Plan, Learn, Act, Now!) is a model for youth civic engagement in city planning that uses urban space slated for redevelopment as a catalyst for community revitalization and education reform. The program partners graduate level mentors, high school students, government agencies, private interests, and other community members who work together on a real-world planning problem. This article analyzes the data produced by Y-PLAN between 2000 and 2005 and demonstrates the model's effectiveness in fostering positive community outcomes and meaningful learning experiences, as well as its theoretical implications for the planning and education fields. We have identified three central conditions on which the success of the Y-PLAN rests: 1) authentic problems engage diverse stakeholders and foster a "community of practice"; 2) adult and youth partners share decision-making; and 3) projects build sustainable individual and institutional success.