After more than a decade of rapid population growth and a thriving economy, Phoenix’s once-booming health care market has recently adopted a more cautious outlook. Job losses and the subsequent loss of employer-sponsored health insurance, along with a high rate of home foreclosures, have adversely affected many Phoenix residents. At the same time, employers, especially small firms, and health plans have continued to search for ways to reduce health insurance premiums. In response, area hospitals and physicians increasingly were seeking closer collaborations and rethinking expansion plans. Against this backdrop of new-found provider caution, significant state-level attention to illegal immigration and a state budget crisis have sparked changes across the area’s health care system.