The group practice "without walls" has become a health care delivery system that is preferred by an increasing number of physicians. This article traces the experience of Premier Medical Group, PC, a "second generation" clinic without walls in the Denver Metropolitan area, to highlight the potential benefits and the key issues related to the development and implementation of a group practice-without-walls model of health-care delivery. The model promises to address physician business and professional needs by building on the best aspects of a traditional group practice, in an overall organizational structure that maximizes each physician's autonomy, individual practice style, and practice identity. The successful implementation of a group practice without walls depends upon physician leadership and impetus, clear goals-and-objectives, competent professional staff, and legal-and-financial guidance.