After reviewing the history of antitrust legislation and established zones of safety for providers and the application of antitrust laws to the healthcare industry in two earlier installments, the authors explore the consequences of the vigorous application of antitrust laws to physician networking, with an emphasis on rural communities. They review common exemptions to antitrust laws that maintain the uneven distribution of power in the evolving healthcare market. Acknowledging the tenuous ground that providers hold in the struggle for control of the healthcare industry, the authors argue for greater consideration of the unique circumstances and barriers that tend to prohibit the formation of strong, physician-sponsored, integrated healthcare networks. The authors have tested the climate for relief from the antitrust enforcement agencies in Washington, DC, and have found no easing of antitrust legislation forthcoming. However, following the resolution of several antitrust cases in recent months, barriers to physician-led organizations appear to be lessening. The authors close with a review of several strategies to minimize the risk of antitrust challenges.