About 47,000 more teens entered the work force in 2012, but only 2,000 found jobs, according to Labor Department data. That pushed up the teenage unemployment rate to 23.5 percent last month, from 22.9 percent in December 2011.
Unemployment fell for all other broad age groups. Americans over age 55 now have an unemployment rate of just 5.9 percent, compared to the national rate of 7.8 percent.
Veterans of the Iraq and Afghanistan wars saw their unemployment rate fall to 10.8 percent from 13.1 percent.
By education, adults without a high school degree saw the best improvement, although their unemployment rate was still high: It fell from 13.7 percent to 11.7 percent.
By contrast, only 3.9 percent of adults with a college degree were unemployed in December 2012, down only one-tenth from a year earlier.