OBJECTIVE CDC began abortion surveillance in 1969 to document the number and characteristics of women obtaining legal induced abortions and to monitor unintended pregnancy. METHODS This report summarizes and describes data reported to CDC regarding legal induced abortions obtained in the United States in 1999. METHODS For each year since 1969, CDC has compiled abortion data by state or area of occurrence. From 1973 through 1997, data were received from or estimated for 52 reporting areas in the United States: 50 states, the District of Columbia, and New York City. Beginning in 1998, CDC compiled abortion data from 48 reporting areas. Alaska, California, New Hampshire, and Oklahoma did not report, and data for these areas were not estimated. The availability of data regarding the characteristics of women who obtained an abortion in 1999 varied by state and by the number of states reporting each characteristic. The total number of legal induced abortions is reported by state of residence and also by state of occurrence for most areas; characteristics of women obtaining abortions in 1999 are reported by state of occurrence. RESULTS A total of 861,789 legal induced abortions were reported to CDC for 1999, representing a 2.5% decrease from the 884,273 legal induced abortions reported by the same 48 reporting areas for 1998. The abortion ratio, defined as the number of abortions per 1,000 live births, was 256 in 1999, compared with 264 reported for 1998; the abortion rate for these 48 reporting areas was 17 per 1,000 women aged 15-44 years for 1999, the same as in 1997 and 1998. The highest percentages of abortions were reported for women aged < 25 years, women who were white, and unmarried women; slightly more than half were obtaining an abortion for the first time. Fifty-eight percent of all abortions for which gestational age was reported were performed at < or = 8 weeks of gestation, and 88% were performed before 13 weeks. From 1992 (when these data were first collected) through 1999, increases have occurred in the percentage of abortions performed at < or = 6 weeks of gestation. Few abortions were provided after 15 weeks of gestation; 4.3% were obtained at 16-20 weeks and 1.5% were obtained at > or = 21 weeks. A total of 27 reporting areas submitted data stating that they performed medical (nonsurgical) procedures (two of these areas categorized medical abortions with "other" procedures), making up < 1.0% of all procedures reported from all reporting areas. In 1998 (for which data have not been published previously and the most recent year for which such data are available), nine women died as a result of complications from known legal induced abortion; no deaths were associated with known illegal abortion. CONCLUSIONS From 1990 through 1997, the number of legal induced abortions gradually declined. In 1998 and in 1999, the number of abortions continued to decrease when comparing the same 48 reporting areas. In 1998, as in previous years, deaths related to legal induced abortions occurred rarely. CONCLUSIONS Abortion surveillance in the United States should continue so that trends and characteristics of women who obtain legal induced abortions can be examined and efforts to prevent unintended pregnancy can be enhanced.