United States dollar
When a Federal Reserve Bank receives a cash deposit from a bank, it checks the individual notes to determine whether they are fit for future circulation. About one-third of the notes that the Fed receives are not fit, and the Fed destroys them. As shown in the table below, the life of a note varies according to its denomination. For example, a $1 bill, which gets the greatest use, remains in circulation an average of 5.9 years; a $100 bill lasts about 15 years.