The 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.
"Preventing teen pregnancy can protect the health and quality of life of teenagers, their children, and their families throughout the United States," he said.
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.
The report says teen childbirth is highest among Hispanics and non-Hispanic blacks. Blacks and Hispanic teen girls are two to three times more likely to give birth than white teens.