The percentage of Americans with high medical cost burdens—those who spend more than 10 percent of their family income on out-of-pocket expenses for health care—increased to 19.2 percent in 2011, after having stabilized at 18.2 percent during the Great Recession of 2007–09. The increase was driven primarily by growth in premium expenses in 2009–11 for people with employer-sponsored coverage. Out-of-pocket spending on health services, especially for prescription drugs, continued to decrease between 2007–09 and 2011. Medical cost burdens were highest for income groups most likely to benefit from the Affordable Care Act’s coverage expansions, including people with private insurance coverage. Those who purchased nongroup coverage before the implementation of the health insurance Marketplaces in 2014 spent an especially high proportion of their income on health care, and over half of these people will qualify for premium subsidies in the Marketplaces. Federal subsidies will substantially reduce medical cost burdens for many people who do not obtain health insurance through their employers.