Background: The incidence of unintended pregnancy is among the most essential health status indicators in the field of reproductive health. One ongoing goal of the US Department of Health and Human Services is to reduce unintended pregnancy, but the national rate has not been estimated since 2001. Study Design: We combined data on women's pregnancy intentions from the 2006–2008 and 2002 National Survey of Family Growth with a 2008 national survey of abortion patients and data on births from the National Center for Health Statistics, induced abortions from a national abortion provider census, miscarriages estimated from the National Survey of Family Growth and population data from the US Census Bureau. Results: Nearly half (49%) of pregnancies were unintended in 2006, up slightly from 2001 (48%). The unintended pregnancy rate increased to 52 per 1000 aged 15–44 years in 2006 from 50 in 2001. Disparities in unintended pregnancy rates among subgroups persisted and in some cases increased, and women who were 18–24 years old, poor or cohabiting had rates two to three times the national rate. The unintended pregnancy rate declined notably for teens 15–17 years old. The proportion of unintended pregnancies ending in abortion decreased from 47% in 2001 to 43% in 2006, and the unintended birth rate increased from 23 to 25 per 1000 women 15–44 years old. Conclusions: Since 2001, the United States has not made progress in reducing unintended pregnancy. Rates increased for nearly all groups and remain high overall. Efforts to help women and couples plan their pregnancies, such as increasing access to effective contraceptives, should focus on groups at greatest risk for unintended pregnancy, particularly poor and cohabiting women.