How should physicians respond to the growing tension between care and cost? One option is to reinforce the ideal of doing everything to further the best interests of the individual patient. Others, however, have argued that because health care resources are shared and limited, physicians should consciously participate in rationing by saying "no" to patients' requests for some marginally beneficial services. But even physicians who endorse the idea of rationing wonder whether patient-physician relationships could ever survive a frank admission of rationing at the bedside. This article explores the idea that caring about costs can be brought to the bedside in a way that will sustain trust among patients and the public. By illustrating a hypothetical case and the ensuing conversation between a physician and her patient, a mode of "proportional" patient advocacy is presented in which physicians can remain forceful agents for patient good while acting within a framework that admits to the boundaries of responsible budgets for health care needs.