15% of 55- to 64-year-olds are retired, down from 17% ten years ago.
"Fewer 55- to 64-year-olds reported being retired in 2012-2013 (14.6%) than a decade earlier [2002-2003] (17.0%), while the percentage not employed due to disability rose from 11.5% to 12.7%, and the percentage employed remained the same at approximately 60%," according to a 2015 report from the Centers for Disease Control.
Centers for Disease Control. (2015). Health, United States, 2014, with special feature on adults aged 55-64. (p. 22) Hyattsville, MD: Department of Health and Human Services. Retrieved from http://www.cdc.gov