1.8 million people enrolled in state and federal marketplaces in Dec. WASHINGTON, Jan. 13 (UPI) -- The Obama administration says 30 percent of the people who've selected health insurance plans from state and federal marketplaces are under the age of 35. A report released Monday by the Department of Health and Human Services shows 30 percent of the 2.2 million people who enrolled in the state and federal marketplaces by Dec. 28 are under the age of 35, and 24 percent are between the ages of 18 and 34. The report said 1.8 million people enrolled in state and federal marketplaces in December, a five-fold increase from the cumulative number reported for October and November. Fifty-four percent of those who selected healthcare plans from Oct. 1 through Dec. 28 are female. Sixty percent selected a Silver plan and 20 percent selected a Bronze plan. Seventy-nine percent who have selected a plan from the online marketplace will receive federal financial assistance in paying their premiums, the report said.