How to replace it: For federal savings bonds, go to the U.S. Treasury's website (treasurydirect.gov) and fill out Form 1048. You can find missing savings bonds all the way back to 1935.
For registered federal Treasury bonds, you have to write a letter to the government (the address is on the Treasury website) and request a search.
Cost: Free for savings bonds; for Treasury bonds, fee varies.
Last updated December 31 2007: 8:33 AM ET