In December 2000 Congress enabled the Omnibus Appropriation Act (PL 106-554). That act included amendments to federal statutes dealing with the interest rate on federal judgments. One of the changes is establishment of a new interest rate index. For judgments entered on and after December 21, 2000 the rate is based on "...the weekly average 1-year constant maturity Treasury yield, as published by the Board of Governors of the Federal Reserve System, for the calendar week preceding the first day on which the defendant is liable for interest..." The applicable rate is listed under US Government Securities - Treasure Constant Maturities - 1 year. The specific rate is found under the column headed week ending MM/DD, where MM/DD is the month and week ending date.
Rates beginning with the week ending February 23, 2001 can be located at the Federal Reserve's website: http://www.federalreserve.gov/releases/H15/Current