(a) Scope. This section identifies exceptions to the acceleration events, which, like the rules regarding acceleration events provided in § 1.721(c)-4(b), apply on a property-by-property basis. Paragraph (b) of this section identifies the events that terminate the requirement to apply the gain deferral method. Paragraph (c) of this section identifies the successor events that allow for the continued application of the gain deferral method. Paragraph (d) of this section identifies the partial acceleration events. Paragraph (e) of this section provides special rules for transfers of section 721(c) property to a foreign corporation described in section 367. Paragraph (f) of this section allows for the continued application of the gain deferral method if there is a fully taxable disposition of a portion of an interest in a partnership. Paragraph (g) of this section provides the dates of applicability. For definitions that apply for purposes of this section, see § 1.721(c)-1(b).

(b) Termination events—(1) In general. Notwithstanding § 1.721(c)-4(b)(1), a termination event with respect to section 721(c) property will not constitute an acceleration event. In these cases, the section 721(c) property will no longer be subject to the gain deferral method.

(2) Transfers of section 721(c) property (other than a partnership interest) to a domestic corporation described in section 351. A termination event occurs if a section 721(c) partnership transfers section 721(c) property (other than an interest in a partnership) to a domestic corporation in a transaction to which section 351 applies.

(3) Certain incorporations of a section 721(c) partnership. A termination event occurs upon an incorporation of a section 721(c) partnership into a domestic corporation by any method of incorporation (other than a method involving an actual distribution of partnership property to the partners, followed by a contribution of that property to a corporation), provided that the section 721(c) partnership is liquidated as part of the incorporation transaction.

(4) Certain distributions of section 721(c) property. A termination event occurs if a section 721(c) partnership distributes section 721(c) property either to the U.S. transferor or, if the U.S. transferor is a member of a consolidated group (as defined in § 1.1502-1(h)) at the time of the distribution and the distribution occurs outside the seven-year period described in section 704(c)(1)(B), to a member of the consolidated group.

(5) Partnership ceases to have a partner that is a related foreign person. A termination event occurs when a section 721(c) partnership ceases to have any direct or indirect partners that are related foreign persons with respect to the U.S. transferor, provided there is no plan for a related foreign person to subsequently become a direct or indirect partner in the partnership (or a successor). This paragraph (b)(5) does not apply to a distribution of section 721(c) property in redemption of a related foreign person's interest in a section 721(c) partnership.

(6) Fully taxable dispositions of section 721(c) property. A termination event occurs if a section 721(c) partnership disposes of section 721(c) property in a transaction in which all gain or loss, if any, is recognized.

(7) Fully taxable dispositions of an entire interest in a section 721(c) partnership. A termination event occurs if a U.S. transferor or a partnership in which a U.S. transferor is a direct or indirect partner disposes of its entire interest in a section 721(c) partnership that owns the section 721(c) property in a transaction in which all gain or loss, if any, is recognized. This paragraph (b)(7) does not apply if a U.S. transferor is a member of a consolidated group (as defined in § 1.1502-1(h)) and the interest in the section 721(c) partnership is transferred in an intercompany transaction (as defined in § 1.1502-13(b)(1)); see paragraph (c)(3) of this section for a successor event rule applicable to these intercompany transactions.

(c) Successor events—(1) In general. Notwithstanding § 1.721(c)-4(b)(1), a successor event with respect to section 721(c) property will not constitute an acceleration event. If a portion of an interest in a partnership is transferred in a successor event described in this paragraph (c), the principles of § 1.704-3(a)(7) apply to determine the remaining built-in gain in section 721(c) property that is attributable to the portion of the interest that is transferred and the portion of the interest that is retained.

(2) Transfers of an interest in a section 721(c) partnership by a U.S. transferor or upper-tier partnership to a domestic corporation in certain nonrecognition transactions. A successor event occurs if a U.S. transferor or a partnership in which a U.S. transferor is a direct or indirect partner transfers (directly or indirectly through one or more partnerships) an interest in a section 721(c) partnership to a domestic corporation in a transaction to which section 351 or 381 applies, and the gain deferral method is continued by treating the transferee domestic corporation as the U.S. transferor for purposes of the section 721(c) regulations. If the transfer described in this paragraph (c)(2) also results in a termination under section 708(b)(1)(B) of the section 721(c) partnership, see paragraph (c)(4) of this section.

(3) Transfers of an interest in a section 721(c) partnership in an intercompany transaction. A successor event occurs if a U.S. transferor that is a member of a consolidated group (as defined in § 1.1502-1(h)) transfers (directly or indirectly through one or more partnerships) an interest in a section 721(c) partnership in an intercompany transaction (as defined in § 1.1502-13(b)(1)), and the gain deferral method is continued by treating the transferee member as the U.S. transferor for purposes of the section 721(c) regulations. If the transfer described in this paragraph (c)(3) also results in a termination under section 708(b)(1)(B) of the section 721(c) partnership, see paragraph (c)(4) of this section.

(4) Termination under section 708(b)(1)(B) of a section 721(c) partnership. A successor event occurs if there is a termination under section 708(b)(1)(B) of a section 721(c) partnership, and the gain deferral method is continued by treating the new partnership as the section 721(c) partnership for purposes of the section 721(c) regulations.

(5) Transactions involving tiered partnerships—(i) Contributions of section 721(c) property to a lower-tier partnership. A successor event occurs if a section 721(c) partnership contributes the section 721(c) property to a partnership that is a controlled partnership with respect to the U.S. transferor (lower-tier section 721(c) partnership) and the requirements of paragraphs (c)(5)(i)(A) through (C) of this section are satisfied.

(A) The lower-tier section 721(c) partnership is a section 721(c) partnership or is treated as a section 721(c) partnership.

(B) The gain deferral method is applied with respect to the section 721(c) property in the hands of the lower-tier section 721(c) partnership.

(C) The gain deferral method is applied with respect to the section 721(c) partnership's interest in the lower-tier section 721(c) partnership. See § 1.721(c)-3(b)(5) and (d)(2).

(ii) Contributions of an interest in a section 721(c) partnership to an upper-tier partnership. A successor event occurs if a U.S. transferor or a partnership in which a U.S. transferor is a direct or indirect partner contributes (directly or indirectly through one or more partnerships) an interest in a section 721(c) partnership to a partnership that is a controlled partnership with respect to the U.S. transferor (upper-tier section 721(c) partnership) and the requirements of paragraphs (c)(5)(ii)(A) through (D) of this section are satisfied.

(A) The gain deferral method is continued with respect to the section 721(c) property in the hands of the section 721(c) partnership.

(B) The upper-tier section 721(c) partnership is, or is treated as, a section 721(c) partnership.

(C) If the upper-tier section 721(c) partnership directly owns its interest in the section 721(c) partnership, the gain deferral method is applied with respect to the upper-tier section 721(c) partnership's interest in the section 721(c) partnership. See § 1.721(c)-3(b)(5) and (d)(1).

(D) If the upper-tier section 721(c) partnership indirectly owns its interest in the section 721(c) partnership through one or more partnerships, the principles of paragraphs (c)(5)(ii)(B) and (C) of this section are applied with respect to each partnership through which the upper-tier section 721(c) partnership indirectly owns an interest in the section 721(c) partnership.

(d) Partial acceleration events—(1) In general. Notwithstanding § 1.721(c)-4, a partial acceleration event with respect to section 721(c) property does not constitute an acceleration event. In these cases, except as provided in paragraph (d)(3) of this section, the rules in § 1.721(c)-4(c) (concerning the consequences of an acceleration event) for making basis adjustments apply to the extent that the U.S. transferor is required to recognize gain under paragraph (d)(2) or (3) of this section. Furthermore, if there is remaining built-in gain with respect to the section 721(c) property after the application of this paragraph (d), the application of the gain deferral method with respect to the section 721(c) property must be continued in the same manner.

(2) Regulatory allocations. If a regulatory allocation is described in § 1.721(c)-3(c)(4)(i) but not in § 1.721(c)-3(c)(4)(i)(A) or (B), a partial acceleration event occurs with respect to section 721(c) property if the U.S. transferor recognizes an amount of gain (but not in excess of remaining built-in gain) equal to the amount of the allocation that, under the consistent allocation method, had the regulatory allocation not occurred, would have been allocated to the U.S. transferor in the case of income or gain, or would not have been allocated to the U.S. transferor in the case of deduction or loss.

(3) Certain distributions of other partnership property to a partner that result in an adjustment under section 734. A partial acceleration event occurs with respect to section 721(c) property if there is a distribution of other property by the section 721(c) partnership that results in a positive basis adjustment to the section 721(c) property under section 734. In these cases, the U.S. transferor must recognize an amount of gain (but not in excess of the remaining built-in gain) equal to the positive basis adjustment to the section 721(c) property under section 734, reduced (but not below zero) by the amount of gain recognized by the U.S. transferor (or a member of its consolidated group (as defined in § 1.1502-1(h))) under section 731(a). In these cases, the partnership will not increase its basis under § 1.721(c)-4(c)(2) by the amount of gain recognized by the U.S. transferor.

(e) Transfers described in section 367 of section 721(c) property to a foreign corporation. If a section 721(c) partnership transfers section 721(c) property, or a U.S. transferor or a partnership in which a U.S. transferor is a direct or indirect partner transfers (directly or indirectly through one or more partnerships) all or a portion of an interest in a section 721(c) partnership that owns section 721(c) property, to a foreign corporation in a transaction described in section 367, then the property will no longer be subject to the gain deferral method. To the extent any U.S. transferor is treated as transferring the section 721(c) property to the foreign corporation for purposes of section 367, the tax consequences will be determined under section 367. In this regard, see §§ 1.367(a)-1T(c)(3)(i) and (ii), 1.367(d)-1T(d)(1), and 1.367(e)-2(b)(1)(iii) (providing for the aggregate treatment of partnerships). However, for the remaining portion of the property (if any), the U.S. transferor must recognize an amount of gain equal to the remaining built-in gain that would have been allocated to the U.S. transferor if the section 721(c) partnership had sold that portion of the section 721(c) property immediately before the transfer for fair market value. The stock in the transferee foreign corporation received will not be subject to the gain deferral method. The rules in § 1.721(c)-4(c) (concerning the consequences of an acceleration event) for making basis adjustments will apply to the extent that the U.S. transferor recognizes gain under this paragraph (e).

(f) Fully taxable dispositions of a portion of an interest in a partnership. If a U.S. transferor or a partnership in which a U.S. transferor is a direct or indirect partner disposes of (directly or indirectly through one or more partnerships) a portion of an interest in a section 721(c) partnership in a transaction in which all gain or loss, if any, is recognized, an acceleration event will not occur with respect to the portion of the interest transferred. The gain deferral method will continue to apply with respect to the section 721(c) property of the section 721(c) partnership. The principles of § 1.704-3(a)(7) will apply to determine the remaining built-in gain in section 721(c) property that is attributable to the portion of the interest in a section 721(c) partnership that is retained. This paragraph (f) will not apply to an intercompany transaction (as defined in § 1.1502-13(b)(1)).

(g) Applicability dates—(1) In general. Except as provided in paragraph (g)(2) of this section, this section applies to contributions occurring on or after January 18, 2017, and to contributions that occurred before January 18, 2017 resulting from an entity classification election made under § 301.7701-3 of this chapter that was effective on or before January 18, 2017 but was filed on or after January 18, 2017.

(2) Election to apply this section retroactively. This section may, by election, be applied to a contribution that occurred on or after August 6, 2015 but before January 18, 2017, and to a contribution that occurred before August 6, 2015 resulting from an entity classification election made under § 301.7701-3 of this chapter that was effective on or before August 6, 2015 but was filed on or after August 6, 2015. The election must have been made by applying this section to the contribution on a timely filed original return (including extensions) or an amended return filed no later than July 18, 2017.