(a) The augmented estate is the estate, first, reduced by the aggregate amount of funeral and administration expenses, homestead allowance, family allowances and exemptions, and enforceable claims and, second, increased by the aggregate amount of the following items:
(1) The value of property transferred by the decedent at any time during marriage to the surviving spouse to or for the benefit of any person other than a bona fide purchaser or the surviving spouse, but only to the extent to which the decedent did not receive adequate and full consideration in money or money's worth for such transfer, if such transfer is a transfer of any of the following types:
(i) Any transfer under which the decedent retained at death the possession or enjoyment of, or right to income from, the property;
(ii) Any transfer to the extent to which the decedent retained at death a power alone or with any other person to revoke such transfer or to consume, invade, or dispose of the principal of the property for his or her own benefit;
(iii) Any transfer whereby the property is held at death by the decedent and any other person or persons with right of survivorship; or
(iv) Any transfer to a donee or donees made by the decedent within three years of death to the extent to which the aggregate amount of such transfers to any one donee in any of such years exceeded three thousand dollars; and
(2) The value of property owned by the surviving spouse at death of the decedent and the value of property transferred by the surviving spouse at any time during marriage to the decedent to or for the benefit of any person other than the decedent, but exclusive of all income earned thereby before death of the decedent and only to the extent both to which such property would have been included in the augmented estate of the surviving spouse if the surviving spouse had predeceased the decedent and to which such property is derived from the decedent by any means other than testate or intestate succession without adequate and full consideration in money or money's worth, if such property is property of any of the following types:
(i) Any property derived from the decedent including, without limitation to, any beneficial interest of the surviving spouse in a trust created by the decedent during his or her lifetime, any property appointed to the surviving spouse by the exercise by the decedent of a general or a special power of appointment also exercisable in favor of any person other than the surviving spouse, any proceeds, including accidental death benefits, of insurance upon the life of the decedent together with any lump sum immediately payable and the commuted value of any proceeds of annuity contracts under which the decedent was the primary annuitant attributable to the premiums for such insurance paid by the decedent or by his or her employer, his or her partner, a partnership of which he or she was a member, or any of his or her creditors, the commuted value of any amounts or proceeds payable after death of the decedent under public or private pension, disability, compensation, death benefit, or retirement plan, exclusive of the federal social security, railroad retirement, or like system, by reason of service performed or disability incurred by the decedent, and the value of any share of the surviving spouse resulting from rights in community property in Nebraska or elsewhere formerly owned with the decedent; or
(ii) Any property owned by the surviving spouse at death of the decedent or previously transferred by the surviving spouse, except to the extent to which the surviving spouse establishes that such property was derived from any source other than the decedent.
A bona fide purchaser under (1) above is a purchaser for value in good faith and without notice of any adverse claim; and the attachment of stamps to an instrument and their cancellation under sections 76-901 to 76-908 are prima facie evidence that the transferee of the transfer thereby effected is a bona fide purchaser.
(b) Property included in the augmented estate under subsection (a) of this section is valued at the following dates:
(1) For property transferred by the decedent by irrevocable gift during lifetime, at the date, if before death of the decedent, the donee first came into possession or enjoyment of such property;
(2) For property transferred by the surviving spouse of the decedent, at the date, if before death of the decedent, such transfer became irrevocable; and
(3) For all property not valued at any other date, at the date of death of the decedent.
(c) The augmented estate does not include the following items otherwise includable under subsection (a) of this section:
(1) Accident or life insurance proceeds, joint annuity, or pension payable to any person other than the surviving spouse of the decedent;
(2) Property transferred by the decedent to any person other than the surviving spouse by any bill of sale, conveyance, deed, or gift or by any other means of transfer either by an instrument of transfer joined in by the surviving spouse of the decedent or with the consent to transfer manifested before or after death of the decedent by a writing signed by the surviving spouse of the decedent before, contemporaneously with, or after the transfer; and
(3) Property transferred by or from the decedent to any person by any means other than intestate succession or testamentary disposition if a petition is not filed or delivered under section 30-2317 within nine months of the death of the decedent.