U.S. Series I bonds are government savings bonds that are issued by the Treasury in small denominations (as small as $25). Series I bonds have variable interest rates that are linked to inflation and a specified real rate of return.

Series I bonds, like Series EE bonds, are liquid in the sense that they can be cashed at any time. Ideally, you should hold them for at least five years to ensure that there will be no interest penalty, and after that they are very liquid and can be cashed at any bank. Interest rates are variable and change with inflation. Required minimum balances are low, and bonds can be purchased in denominations ranging from $25 to $10,000. Series I bonds are very secure because they have an implicit government guarantee. There is a three-month interest penalty for early withdrawal if you cash these bonds before five years. Other features include interest being exempt from state and local income tax; interest may even be tax free if the interest and principal are spent on eligible college expenses (mainly tuition and fees). Because interest is not paid until maturity, there are no taxes on interest until the bond is redeemed. Information on rates and how to purchase Series I bonds can be found at www.Savingsbonds.gov. Series I bonds have the same MAGI limits as Series EE bonds listed on the previous page.