Series I Bonds are a low-risk, liquid savings product. While you own them they earn interest and protect you from inflation.

Earnings rates for I bonds are set each May 1 and November 1. Interest accrues monthly and compounds semiannually. Bonds held less than five years are subject to a three-month interest penalty. I Bonds have an interest-bearing life of 30 years.  When the inflation rate is less than zero, a bond's earnings rate is less than its fixed rate (but the earnings rate is never less than zero)

November 2, 2015 Update:  The Current I Bond Composite Earnings Rate is 1.64% with a Fixed Rate of 0.10%.

For rates on I Bonds bought before this period, see:

• Current Interest Rates for Older Series-I Bonds
• More information at New Series I Bonds Offer Attractive Rates, a Seeking Alpha Article

The earnings rate for Series I Savings Bonds is a combination of a fixed rate, which applies for the life of the bond, and the semiannual inflation rate. The 1.48% earnings rate for I bonds bought from November 2014 through April 2015 applies for the first six months after the issue date.

The earnings rate combines a 0.00% fixed rate of return with the 1.48% annualized rate of inflation as measured by the Consumer Price Index for all Urban Consumers (CPI-U). The CPI-U increased from 236.293 in March 2014 to 238.031 in September 2014, a six-month increase of 0.74%.

• Fixed rate  = 0.00%
• 6 month Inflation rate = 0.74%
• Composite rate =[fixed rate + (2 x inflation rate) + (fixed rate x inflation rate)]
  [0.0000 + (2 x 0.0074) + ( 0.0000 x 0.0074)]= 0.0148 = 1.48%

Composite Rate History

Fixed Rate History

CPI Table

Best Time to Buy I Bonds:  Near the end of the month.  Make sure you leave enough time for funds to clear.

Best Time to Sell I Bonds:  At the start of the month since interest for the prior month is computed on the first of each month.  You don't earn interest for fractional months so sell only after the new interest shows up in your account, usually the first of the month,

I Bond Composite rate = [Fixed rate + (2 x Inflation rate) + (Fixed rate x Inflation rate)]

Where to Buy I Bonds?    You may purchase I Bonds at www.TreasuryDirect.gov.