If you have the serial numbers, the Bureau of Public Debt can look up the status of the securities, assuming they are U.S. Treasury securities. To do so, a signed request by the owner or co-owner must be received by the Bureau of Public Debt before infomration can be provided. If the bond owner or both co-owners are deceased, then the person making the request needs to provide proof, such as a copy of the death certificate(s). Send the request to: Bureau of the Public Debt, P.O. Box 7012, Parkersburg, WV 26106-7012.