Series EE savings bonds look unexciting — today’s fixed rate is just 2.40% — until you understand the 20-year doubling guarantee, which is the real reason to own them.
How the guarantee works
The Treasury promises that an EE bond held for 20 years will be worth at least twice what you paid. The bond earns its fixed rate (2.40% now) compounding semiannually; if that hasn’t doubled the bond by year 20, the Treasury makes a one-time adjustment at the 20-year mark to bring it to exactly 2x.
| Hold period | What you get (today’s 2.40% rate) |
|---|---|
| 10 years | ~1.27× (fixed rate only) |
| 19 years | ~1.57× (fixed rate only) |
| 20 years | 2.00× (guaranteed double) |
The jump from year 19 to year 20 is the guarantee kicking in. See it for any amount in the EE doubling calculator.
The effective return
Doubling in exactly 20 years is an annual yield of about 3.5% (2^(1/20) − 1 ≈ 3.53%). That’s the number to compare against other 20-year fixed options — and it beats the 2.40% the bond quotes, because the quoted rate ignores the year-20 top-up.
When EE bonds make sense
- You can lock the money away for the full 20 years.
- You want a known, guaranteed outcome rather than a variable rate.
- You’ve used your I bond allowance and want a separate $10,000 in a predictable long-term bond.
If you might need the money sooner, an I bond (currently 4.26%, inflation-protected, more flexible) is usually the better fit. Review the EE rate history and EE bonds explained. Not investment advice.