Summarize this article:

You can redeem EE, E, and I savings bonds 12 months after you purchase them. However, you will pay penalties and lose accrued interest if you redeem them before they fully mature.  Redeeming an I or EE bond before it is 5 years old will result in the loss of the last 3 months of accrued interest.  I and EE bonds earn interest for 30 years if you don't redeem them. All bonds are guaranteed at least their face value by 20 years. If you are cashing in a savings bond issued in April 1997 or earlier, then you need to redeem it in the correct time of year to make sure you don't lose interest. These bonds accrue interest every 6 months, so if you redeem it near the end of the 6 month period, you will lose that 6 month period's interest. Determine which month the bond was issued in. Redeem the bond in that month or 6 months from the issue month. For example, if your bond was issued in January, you want to redeem the bond in January or July. If the bond was issued in October, you want to redeem it in either October or April. To redeem a savings bond, you must be the owner, co-owner, or entitled individual. An entitled individual includes someone with Power of Attorney or a Legal Guardian.  If you are a beneficiary for someone deceased, you must bring a death certificate to provide proof you can cash the bond. If you are a parent or guardian, you must bring a birth certificate or other identification materials if you wish to cash the bond for your child.  An owner or co-owner can cash the bond without the knowledge of the other person.
Make sure the bond is eligible for redemption. Redeem the bond at the correct time of year. Determine if you are eligible to redeem the bond.