Flexibility sets planned unit developments (PUD) apart from conventional planning and zoning. Using a case study of a PUD project in Ann Arbor, Michigan, I deconstruct the impact of flexibility on the planning process. I find that flexibility emphasizes negotiated decision making in an unconducive institutional setting, results in uncertainty for all actors involved, makes public interest a moving target, and replaces bureaucratic procedures with politics. Although PUDs provide reprieve from local codes and plans, my findings highlight how important it is for municipalities to ensure that the underlying development management framework is of good quality for effective PUD implementation.