SECTION 406. OBLIGATION TO PAY MONEY.

(a) An amount received as interest, whether determined at a fixed, variable, or floating rate, on an obligation to pay money to the trustee, including an amount received as consideration for prepaying principal, must be allocated to income without any provision for amortization of premium.

(b) A trustee shall allocate to principal an amount received from the sale, redemption, or other disposition of an obligation to pay money to the trustee more than one year after it is purchased or acquired by the trustee, including an obligation whose purchase price or value when it is acquired is less than its value at maturity. If the obligation matures within one year after it is purchased or acquired by the trustee, an amount received in excess of its purchase price or its value when acquired by the trust must be allocated to income.

(c) This section does not apply to an obligation to which Section 409, 410, 411, 412, 414, or 415 applies.

Variable or floating interest rates. The reference in subsection (a) to variable or floating interest rate obligations is intended to clarify that, even though an obligation's interest rate may change from time to time based upon changes in an index or other market indicator, an obligation to pay money containing a variable or floating rate provision is subject to this section and is not to be treated as a derivative financial instrument under Section 414.

Discount obligations. Subsection (b) applies to all obligations acquired at a discount, including short-term obligations such as U.S. Treasury Bills, long-term obligations such as U.S. Savings Bonds, zero-coupon bonds, and discount bonds that pay interest during part, but not all, of the period before maturity. Under subsection (b), the entire increase in value of these obligations is principal when the trustee receives the proceeds from the disposition unless the obligation, when acquired, has a maturity of less than one year. In order to have one rule that applies to all discount obligations, the Act eliminates the provision in the 1962 Act for the payment from principal of an amount equal to the increase in the value of U.S. Series E bonds. The provision for bonds that mature within one year after acquisition by the trustee is derived from the Illinois act. 760 ILCS 15/8 (1996).

Subsection (b) also applies to inflation-indexed bonds - any increase in principal due to inflation after issuance is principal upon redemption if the bond matures more than one year after the trustee acquires it; if it matures within one year, all of the increase, including any attributable to an inflation adjustment, is income.

Effect of Section 104. In deciding whether and to what extent to exercise the power to adjust between principal and income granted by Section 104(a), a relevant factor for the trustee to consider is the effect on the portfolio as a whole of having a portion of the assets invested in bonds that do not pay interest currently.