In 1994, publicly traded HMOs completed 13 acquisitions valued at over $4 billion. Two hospital chains, Columbia/HCA and National Medical Enterprises, recently completed mergers that give them ownership of 61% of the for-profit hospital beds in the United States. The Wall Street Journal predicts that within a year 10 publicly traded physician practice companies will be competing for a potential $200 billion market. Such concentrated market power could make the health care system more efficientand less expensiveor, paradoxically, could produce higher prices and fewer choices for consumers.