the excess of the taxpayer’s contribution base (as defined in subparagraph (H) of section 170(b)(1) of such Code) over the amount of all other charitable contributions allowed under section 170(b)(1) of such Code. (ii) Carryover If the aggregate amount of qualified contributions made in the contribution year (within the meaning of section 170(d)(1) of such Code) exceeds the limitation of clause (i), such excess shall be added to the excess described in section 170(b)(1)(G)(ii). (B) Corporations In the case of a corporation— (i) Limitation Any qualified contribution shall be allowed as a deduction only to the extent that the aggregate of such contributions does not exceed the excess of 25 percent of the taxpayer’s taxable income (as determined under paragraph (2) of section 170(b) of such Code) over the amount of all other charitable contributions allowed under such paragraph. (ii) Carryover If the aggregate amount of qualified contributions made in the contribution year (within the meaning of section 170(d)(2) of such Code) exceeds the limitation of clause (i), such excess shall be appropriately taken into account under section 170(d)(2) subject to the limitations thereof. (3) Qualified contributions (A) In general For purposes of this subsection, the term qualified contribution means any charitable contribution (as defined in section 170(c) of the Internal Revenue Code of 1986) if— (i) such contribution is paid in cash during calendar year 2020 to an organization described in section 170(b)(1)(A) of such Code, and (ii) the taxpayer has elected the application of this section with respect to such contribution. (B) Exception Such term shall not include a contribution by a donor if the contribution is— (i) to an organization described in section 509(a)(3) of the Internal Revenue Code of 1986, or (ii) for the establishment of a new, or maintenance of an existing, donor advised fund (as defined in section 4966(d)(2) of such Code). (C) Application of election to partnerships and s corporations In the case of a