Final answer:
A Series EE bond has a recommended holding period of 20 years to receive the maximum return on investment.
Step-by-step explanation:
The Series EE bond is a type of savings bond issued by the U.S. Treasury. The bond has a maturity period of 30 years. However, to receive the maximum return on your investment, it's recommended to hold the bond for at least 20 years. If you wish to cash the bond before this time, you may face a penalty which could result in a lower return on your investment.