Using the 2001-2009 MEPS, we examine a variety of trends that illustrate patterns of health care use in the U.S. and find that growth rates in per capita spending varied by type of service. We decompose trends into changes in the fraction using services, the intensity of utilization among users, and the cost per unit. We also decompose spending changes into changes in the distribution of individuals' socio-economic characteristics, health insurance status, and prevalence of chronic conditions. We find the majority of the increase in per capita health spending over the decade is explained by factors (e.g., technology growth) outside our model.