26 CFR § 20.2038-1 - Revocable transfers.
(a) In general. A decedent's gross estate includes under section 2038 the value of any interest in property transferred by the decedent, whether in trust or otherwise, if the enjoyment of the interest was subject at the date of the decedent's death to any change through the exercise of a power by the decedent to alter, amend, revoke, or terminate, or if the decedent relinquished such a power in contemplation of death. However, section 2038 does not apply -
(1) To the extent that the transfer was for an adequate and full consideration in money or money's worth (see § 20.2043-1);
(2) If the decedent's power could be exercised only with the consent of all parties having an interest (vested or contingent) in the transferred property, and if the power adds nothing to the rights of the parties under local law; or
(3) To a power held solely by a person other than the decedent. But, for example, if the decedent had the unrestricted power to remove or discharge a trustee at any time and appoint himself trustee, the decedent is considered as having the powers of the trustee. However, this result would not follow if he only had the power to appoint himself trustee under limited conditions which did not exist at the time of his death. (See last two sentences of paragraph (b) of this section.)
(b) Date of existence of power. A power to alter, amend, revoke, or terminate will be considered to have existed at the date of the decedent's death even though the exercise of the power was subject to a precedent giving of notice or even though the alteration, amendment, revocation, or termination would have taken effect only on the expiration of a stated period after the exercise of the power, whether or not on or before the date of the decedent's death notice had been given or the power had been exercised. In determining the value of the gross estate in such cases, the full value of the property transferred subject to the power is discounted for the period required to elapse between the date of the decedent's death and the date upon which the alteration, amendment, revocation, or termination could take effect. In this connection, see especially § 20.2031-7. However, section 2038 is not applicable to a power the exercise of which was subject to a contingency beyond the decedent's control which did not occur before his death (e.g., the death of another person during the decedent's life). See, however, section 2036(a)(2) for the inclusion of property in the decedent's gross estate on account of such a power.
(c) Transfers made before June 23, 1936. Notwithstanding anything to the contrary in paragraphs (a) and (b) of this section, the value of an interest in property transferred by a decedent before June 23, 1936, is not included in his gross estate under section 2038 unless the power to alter, amend, revoke, or terminate was reserved at the time of the transfer. For purposes of this paragraph, the phrase “reserved at the time of the transfer” has reference to a power (arising either by the express terms of the instrument of transfer or by operation of law) to which the transfer was subject when made and which continued to the date of the decedent's death (see paragraph (b) of this section) to be exercisable by the decedent alone or by the decedent in conjunction with any other person or persons. The phrase also has reference to any understanding, express or implied, had in connection with the making of the transfer that the power would later be created or conferred.
(d) Transfers made before June 2, 1924. Notwithstanding anything to the contrary in paragraphs (a) to (c) of this section, if an interest in property was transferred by a decedent before the enactment of the Revenue Act of 1924. (June 2, 1924, 4:01 p.m., eastern standard time), and if a power reserved by the decedent to alter, amend, revoke, or terminate was exercisable by the decedent only in conjunction with a person having a substantial adverse interest in the transferred property, or in conjunction with several persons some or all of whom held such an adverse interest, there is included in the decedent's gross estate only the value of any interest or interests held by a person or persons not required to joint in the exercise of the power plus the value of any insubstantial adverse interest or interests of a person or persons required to join in the exercise of the power.
(e) Powers relinquished in contemplation of death -
(1) In general. If a power to alter, amend, revoke, or terminate would have resulted in the inclusion of an interest in property in a decedent's gross estate under section 2038 if it had been held until the decedent's death, the relinquishment of the power in contemplation of the decedent's death within 3 years before his death results in the inclusion of the same interest in property in the decedent's gross estate, except to the extent that the power was relinquished for an adequate and full consideration in money or money's worth (see § 20.2043-1). For the meaning of the phrase “in contemplation of death”, see paragraph (c) of § 20.2035-1.
(2) Transfers before June 23, 1936. In the case of a transfer made before June 23, 1936, section 2038 applies only to a relinquishment made by the decedent. However, in the case of a transfer made after June 22, 1936, section 2038 also applies to a relinquishment made by a person or persons holding the power in conjunction with the decedent, if the relinquishment was made in contemplation of the decedent's death and had the effect of extinguishing the power.
(f) Effect of disability to relinquish power in certain cases. Notwithstanding anything to the contrary in paragraphs (a) through (e) of this section the provisions of this section do not apply to a transfer if -
(1) The relinquishment on or after January 1, 1940, and on or before December 31, 1947, of the power would, by reason of section 1000(e), of the Internal Revenue Code of 1939, be deemed not a transfer of property for the purpose of the gift tax under chapter 4 of the Internal Revenue Code of 1939, and
(2) The decedent was, for a continuous period beginning on or before September 30, 1947, and ending with his death, after August 16, 1954, under a mental disability to relinquish a power.