Accrued interest on Series E or EE bonds will be taxed when they are cashed in. If instead of cashing them in, you trade them for Series HH bonds, that interest on the Series E or EE bonds won't be taxed until the HH bonds mature.
Series E and EE bonds are bought at a discount and accrue interest until they mature, when they are worth their face value. Series HH bonds are issued at face value and pay interest twice a year.
| Series | Issued | Interest for |
| E | May 1941 - Nov 1965 | 40 years |
| E | Dec 1965 & after | 30 years |
| EE | Jan 1980 & after | 30 years |
Check your savings bond portfolio. A Series E bond bought in December 1975 stopped earning interest in December 2005 (although a bond bought in November 1985 will continue accruing interest until November 2015). Likewise, a bond purchased before 1956 has reached the end of its interest-bearing life.