Series EE bonds have been sold since January 1980 — paper EE bonds were bought for half their face value (a $100 bond cost $50), while electronic EE bonds are bought at face value. Enter your bond's denomination and issue date in the calculator to see exactly what it's worth this month, straight from the Treasury's redemption tables.
Every EE bond issued since June 2003 is guaranteed to double its purchase price at 20 years — the Treasury makes a one-time adjustment if interest alone didn't get it there. That works out to about 3.5% a year if you hold to the 20-year mark, usually far more than the bond's stated fixed rate. Cashing an EE bond in year 19 can therefore leave serious money on the table; our calculator's month-by-month values make the jump at the 20-year adjustment easy to see.
Every EE bond issued more than 30 years ago has already stopped earning interest. If you have bonds from the 1980s or early 1990s, check them today — their value is frozen and inflation is eating it. Add them to the inventory and matured bonds are flagged automatically.