The report, released Thursday, finds 11.5 percent of women aged 18 to 44, say they've had at least one sexual experience with another woman at some point in their lifetime. This compares with about 4 percent of women, 18 to 59, who say they had such encounters in a similar survey conducted ten years earlier.
For women in their late teens and 20s, the percentage increased 14 percent in the more recent survey. About 6 percent of men in their teens and 20s say they had at least one same-sex encounter.
While those who conducted the survey took measures to protect participant privacy, researchers say it's unclear whether the figure for men was lower because they are more likely to avoid same-sex experiences or whether they're simply not reporting them.
The findings on bisexuality and other aspects of Americans' sexual habits were taken from the National Survey of Family Growth, which included 12,571 in-person interviews conducted from March 2002 to March 2003.
Generally, researchers say the report shows most people have relatively few partners and are at low risk for sexually transmitted diseases.
