The U.S. Supreme Court case Arizona v. Maricopa County Medical Society et al., 1981, revolved around the issue of whether or not a "maximum fee schedule" for health services agreed upon by a group of doctors violated federal antitrust laws. The maximum fee schedule was essentially an agreement among physicians to charge no more than a certain amount for specific medical services, which was enforced through their participation in two foundations made up of local insurance companies and physicians. The state of Arizona argued that this practice constituted price-fixing and thus infringed on the Sherman Act - legislation designed to prevent monopolies and promote competition in business. In its decision, the Supreme Court ruled against Maricopa County Medical Society with Justice John Paul Stevens writing for majority opinion stating that such agreements did indeed violate antitrust law because they controlled prices regardless of market conditions or individual patient needs thereby limiting competition among providers. This ruling affirmed that professional organizations like these are subject to federal regulation under anti-trust laws even when their actions may be intended to benefit consumers.

In the dissenting opinion for Arizona v. Maricopa County Medical Society, Justice Powell argued that the majority's decision to apply a per se rule against price fixing was inappropriate in this case. He contended that not all agreements among competitors should be considered illegal without further examination of their potential economic impact and benefits. In his view, the Foundation for Medical Care's agreement could potentially improve healthcare quality and accessibility by ensuring reasonable compensation rates for physicians while also providing cost certainty for patients and insurers. Therefore, he believed it deserved a more nuanced analysis under the "rule of reason" rather than an automatic condemnation as price-fixing collusion. Furthermore, he criticized the majority’s reliance on professional associations' opinions instead of empirical evidence or expert testimony when determining whether such arrangements are anti-competitive or beneficial.