The difference between E series and EE series savings bonds is not value but time of issue, according to Treasury Direct, a service of the U.S. Department of the Treasury. The Treasury Department initiated series E savings bonds in 1941 and replaced them with EE series bonds in 1980.
The E series savings bond replaced series A through D at the beginning of World War II to raise funds to defray high defense costs, states Treasury Direct. A massive volunteer program of businesses, bankers, advertising media, community leaders and entertainers helped sell E series bonds, known as War Bonds, during the war years and beyond. E series bonds initially had a fixed term of interest of 10 years, but extensions allowed some bonds to continue to earn interest for up to 30 or 40 years. Although E series bonds stopped earning interest as of 2010, they are still redeemable at a financial institution or by mail at the Federal Reserve Bank of Minneapolis, as of 2015.
In 2012, the Treasury Department stopped issuing new paper EE series bonds, but customers can purchase them electronically online, reports Treasury Direct. The move to eliminate paper bonds is part of a money-saving initiative to switchover exclusively to electronic transactions. EE series bonds earn fixed rates of interest for up to 30 years and are redeemable after one year. There is a penalty of three months interest if they are redeemed before five years, but after five years, there is no penalty.