The U.S. teen pregnancy rate in 2009, the latest year for which data are available, hit its lowest since tracking began 70 years ago, the Center for Disease Control said on Tuesday.
However, more than 400,000 teen girls still give birth a year according to the CDC's Vital Signs report.
"Though we have made progress in reducing teen pregnancy over the past 20 years, still far too many teens are having babies," said CDC director Thomas Frieden in a statement.
The teen birth rate has decreased 37 percent over the last two decades. About four percent of all teenage girls give birth each year, representing about 10 percent of total births, the CDC said.
However, the report says, the current U.S. rate is still as much as nine times higher as that in similar countries.
Forty-six percent of teens have had sexual intercourse, the report said. Out of that number, 14 percent of girls and 10 percent of boys say that they do not use any type of birth control.