What kind of U.S. savings bonds can I buy using this streamlined tax refund method?
Series I U.S. Savings Bonds (“Savings Bonds”). These Series I Savings Bonds are a low-risk, liquid savings product. While you own them, they earn interest and provide protection from inflation. Although Savings Bonds are not marketable, in the sense that they cannot be bought or sold in a secondary securities market, they can generally be redeemed for principal and accrued earnings at any time after 12 months. (See details below.