series EE bonds

I have some bonds dated 1988 how long can I keep these bonds, do I have to cash them after 30 years?

Terry Says:  These Series EE Savings Bonds will reach full maturity in three more years — unless, unlikely, they are extended. At that point, you will have to pay taxes on the accrued interest, so it makes sense to cash them in.  Hold on to them in the meantime, because they have a high base rate.