Little is known about the trends in health care spending for the 156 million Americans who are younger than age sixty-five and enrolled in employer-sponsored health insurance. Using a new source of health insurance claims data, we estimated per capita spending, utilization, and prices for this population between 2007 and 2011. During this period per capita spending on employer-sponsored insurance grew at historically slow rates, but still faster than per capita national health expenditures. Total per capita spending for employer-sponsored insurance grew at an average annual rate of 4.9 percent, with prescription spending growing at 3.3 percent and medical spending growing at 5.3 percent. Out-of-pocket medical spending increased at an average annual rate of 8.0 percent, whereas out-of-pocket prescription drug spending growth was flat. Growth in the use of medical services and prescription drugs slowed. Medical price growth accelerated, and prescription price growth decelerated. As a result, changes in utilization contributed less than changes in price did to overall spending growth for those with employer-sponsored insurance.