where to buy i bonds?

best answer
You can buy electronic I bonds in your TreasuryDirect account. You can buy paper I bonds with your IRS tax refund. How does an I bond earn interest? I savings bonds earn interest monthly. Interest is compounded semiannually meaning that every 6 months we apply the bond’s interest rate to a new principal value. The new principal is the sum of the prior principal and the interest earned in the previous 6 months.