Three types of entities-nonprofit, for-profit, and government-own hospitals. Yet we know neither whether hospital types specialize in different medical services nor how service profitability affects specialization. In this econometric analysis of American Hospital Association data for every U.S. urban, acute care hospital (1988-2000), more than thirty services were categorized as relatively profitable, unprofitable, or variable. For-profits are most likely to offer relatively profitable medical services; government hospitals are most likely to offer relatively unprofitable services; nonprofits often fall in the middle. For-profits are also more responsive to changes in service profitability than the other two types.