When discussing bonds, Term refers to the length of time during which principal and interest payments are made. Short-term bonds run up to 3 years in length. Intermediate bonds are from 3 to 10 years in length. Long-term bonds run up to 30 years in length. Generally, the bonds that pay the highest interest rate are the long-term bonds. However, you’ll only earn an extra percentage point or so on your money and have to tie is up for a long period of time. Financial planners say a better bet is to purchase intermediate-term bonds, which are more flexible.