The number of children in foster care in 1999 was 581,000.  And
297,000 entered foster care in 1999 and 251,000 left foster care in
1999.  In March 1999, the DHSS estimated that 117,000 of the children
in foster care would need adoptive services.  How many children are in
foster care in the US currently, and how many of these children will
need adoptive services?

The Administration for Children and Families statistics posts updates
reports on this page: http://www.acf.hhs.gov/programs/cb/dis/index.htm
. If you are looking for national data, AFCARS Report #9 (Preliminary
Estimates published August 2004) is available at
http://www.acf.hhs.gov/programs/cb/publications/afcars/report9.pdf  .