For purposes of this subtitle, the term “partnership” includes a syndicate, group, pool, joint venture, or other unincorporated organization through or by means of which any business, financial operation, or venture is carried on, and which is not, within the meaning of this title, a corporation or a trust or estate. Under regulations the Secretary may, at the election of all the members of an unincorporated organization, exclude such organization from the application of all or part of this subchapter, if it is availed of—

(1) for investment purposes only and not for the active conduct of a business,

(2) for the joint production, extraction, or use of property, but not for the purpose of selling services or property produced or extracted, or

(3) by dealers in securities for a short period for the purpose of underwriting, selling, or distributing a particular issue of securities,

For purposes of this subtitle, the term “partner” means a member of a partnership. In the case of a capital interest in a partnership in which capital is a material income-producing factor, whether a person is a partner with respect to such interest shall be determined without regard to whether such interest was derived by gift from any other person.

For purposes of this subchapter, a partnership agreement includes any modifications of the partnership agreement made prior to, or at, the time prescribed by law for the filing of the partnership return for the taxable year (not including extensions) which are agreed to by all the partners, or which are adopted in such other manner as may be provided by the partnership agreement.

For purposes of this subchapter, the term “liquidation of a partner’s interest” means the termination of a partner’s entire interest in a partnership by means of a distribution, or a series of distributions, to the partner by the partnership.

Except as otherwise provided in regulations, for purposes of—

(1) section 708 (relating to continuation of partnership),

(2) section 743 (relating to optional adjustment to basis of partnership property), and

(3) any other provision of this subchapter specified in regulations prescribed by the Secretary,

In the case of a qualified joint venture conducted by a husband and wife who file a joint return for the taxable year, for purposes of this title—

In the case of a qualified joint venture conducted by a husband and wife who file a joint return for the taxable year, for purposes of this title—

(A) such joint venture shall not be treated as a partnership,

(B) all items of income, gain, loss, deduction, and credit shall be divided between the spouses in accordance with their respective interests in the venture, and

(C) each spouse shall take into account such spouse’s respective share of such items as if they were attributable to a trade or business conducted by such spouse as a sole proprietor.

For purposes of paragraph (1), the term “qualified joint venture” means any joint venture involving the conduct of a trade or business if—

(A) the only members of such joint venture are a husband and wife,

(B) both spouses materially participate (within the meaning of section 469(h) without regard to paragraph (5) thereof) in such trade or business, and

(C) both spouses elect the application of this subsection.

For rules in the case of the sale, exchange, liquidation, or reduction of a partner’s interest, see sections 704(b) and 706(c)(2).

(Aug. 16, 1954, ch. 736, 68A Stat. 252; Pub. L. 94–455, title II, § 213(c)(3)(B), title XIX, § 1906(b)(13)(A), Oct. 4, 1976, 90 Stat. 1548, 1834; Pub. L. 96–222, title I, § 102(a)(2)(C), Apr. 1, 1980, 94 Stat. 208; Pub. L. 98–369, div. A, title I, § 75(b), July 18, 1984, 98 Stat. 594; Pub. L. 99–514, title XVIII, § 1805(c)(2), Oct. 22, 1986, 100 Stat. 2810; Pub. L. 110–28, title VIII, § 8215(a), May 25, 2007, 121 Stat. 193; Pub. L. 114–74, title XI, § 1102(a), Nov. 2, 2015, 129 Stat. 638.)