(1) Bonds issued from May 1, 1941 through April 1, 1952. Series E bonds with issue dates of May 1, 1941, through April 1, 1952, reached or will reach final maturity 40 years after their respective issue dates, as shown below.

(2) Bonds issued from May 1, 1952 through November 1, 1965. Bonds with issue dates of May 1, 1952, through November 1, 1965, will receive an additional extension of maturity ranging from 4 months to 2 years and 3 months, as shown below, so that these bonds will reach final maturity 40 years after their respective issue dates.

(3) Bonds issued from December 1, 1965 through June 1, 1980. Bonds with issue dates of December 1, 1965, through June 1, 1980, will receive an additional extension of maturity ranging from 3 years to 5 years, as shown below, so that these bonds will reach final maturity 30 years after their respective issue dates.

(1) General. Except as provided in paragraph (c)(2) of this section, the guaranteed minimum investment yields for outstanding Series E bonds are as follows:

(2) Eleven-year bonus. If a bond bearing an issue date of January 1, 1951, or thereafter, was held for the 11-year period from the first semianual interest accrual period that began on or after January 1, 1980, its guaranteed minimum investment yield for such period was increased by one-half of one percent per annum, compounded semiannually.

(1) For each 6-month period, starting with the period beginning May 1, 1982, the average market yield on outstanding marketable Treasury securities with a remaining term to maturity of approximately 5 years during such period is determined. Such determination by the Secretary of the Treasury or his or her delegate shall be final and conclusive.

(2) For bonds which entered an extended maturity period prior to May 1, 1989, the market-based variable investment yield from the first semiannual interest accrual date occurring on or after November 1, 1982 to each semiannual interest accrual date occurring on or after November 1, 1987, will be 85 percent, rounded to the nearest one-fourth of one percent, of the arithmetic average of the market yield averages, as determined in accordance with paragraph (d)(1) of this section, for the appropriate number of 6-month periods involved, starting with the period beginning May 1, 1982.

(3) For bonds which entered an extended maturity period on or after May 1, 1989, the market-based variable investment yield from the first semiannual interest accrual date occurring on or after November 1, 1982 to each semiannual interest accrual date occurring on or after November 1, 1989, will be 85 pecent, rounded to the nearest one-hundredth of one percent, of the arithmetic average of the market yield averages, as determined in accordance with paragraph (d)(1) of this section, for the appropriate number of 6-month periods involved, starting with the period beginning May 1, 1982.

(1) Guaranteed minimum investment yield and resulting values during an extended maturity period. A bond has a guaranteed minimum investment yield for each of its extended maturity periods. The applicable guaranteed minimum investment yields for the current extended maturity period and any subsequent periods are specified in paragraph (c) of this section. In order to determine the value of a bond during an extended maturity period, the value of the bond either at the end of the next preceding maturity period or when the guaranteed minimum investment yield last increased,^[8] whichever occurs later, is determined using the applicable guaranteed minimum investment yield. This value is then used as the base upon which interest accrues during the extended maturity period at the guaranteed minimum investment yield in effect for savings bonds at the beginning of that period. The resulting semiannual values are then compared with the corresponding values determined by using the applicable market-based variable investment yields.

(2) Market-based variable investment yield and resulting values during an extended maturity period. The market-based variable investment yield from the first semiannual interest accrual date occuring on or after November 1, 1982 to each semiannual interest accrual date occurring on or after November 1, 1987, is determined as specified in paragraph (d) of this section. The value of a bond on its first seimannual interest accrual date occurring on or after November 1, 1982 is used as the base upon which interest accrues during an extended maturity period at the applicable market-based variable investment yield. If redeemed, the bond will receive the higher of the two values produced by using the applicable guaranteed minimum investment yield and the applicable market-based variable investment yield.