I hate to break this bad news to you, but all Series EE bonds stop earning interest after 30 years! That means you should have cashed in this bond 10 years ago. AND, that you owed taxes on it as of 10 years ago! Here's a link to the TreasuryDirect.gov website section where you can find out the value of that bond. And nearby you'll also find instructions on cashing in the bon.