Example. An heir of a decedent is entitled to collect an installment obligation with a face value of $100, a fair market value of $80, and a basis in the hands of the decedent of $60. If the heir collects the obligation at face value, the excess of the amount collected over the basis is considered income in respect of a decedent and includible in the gross income of the heir under section 691(a)(1). In this case, the amount includible would be $40 ($100 less $60). If the heir collects the obligation at $90, an amount other than face value, the entire obligation is considered a right to receive income in respect of a decedent but the amount ordinarily required to be included in the heir's gross income under section 691(a)(2) (namely, the consideration received in satisfaction of the installment obligation or its fair market value, whichever is greater) shall be reduced by the amount of the basis of the obligation in the hands of the decedent. In this case, the amount includible would be $30 ($90 less $60).
26 C.F.R. §1.691(a)-5