Anyone who may have unclaimed money owed by the government should visit the unclaimed money portion of the USA.gov site to obtain a list of all institutions to check. As of 2015, the U.S. government does not have a centralized list to check this information.
USA.gov has links to check for unclaimed money by each state, and for federal income tax returns that were unclaimed or undelivered, matured savings bonds, and FHA-insured mortgage refunds. There are also links to check for money that may have been in failed banks or credit unions, unpaid wages and retirement benefits, and SEC claims for money owed by corporations to investors. There is also a link to check for unclaimed money owed by a foreign government for confiscated property.