Since 1990 payment for physician services in the fee-for-service sector has shifted from an open-ended system to fixed global budgets. This shift has created a new economic context for practising medicine in Canada. A global cap creates a conflict between physicians' individual economic self-interest and their collective interest in constraining total billings within the capped budget. These types of incentive problems occur in managing what are known in economics as "common-property resources." Analysts studying common-property resources have documented several management principles associated with successful, long-run use of such resources in the face of these conflicting incentives. These management principles include early defining the boundaries of the common-property resource, explicitly specifying rules for using the resource, developing collective decision-making arrangements and monitoring mechanisms, and creating low-cost conflict-resolution mechanisms. The authors argue that global physician budgets can usefully be viewed as common-property-resources. They describe some of the key management principles and note some implications for physicians and the provincial and territorial medical associations as they adapt to global budgets.