to the eligible taxpayer or any other taxpayer who would be an eligible taxpayer but for paragraph (3) of subsection (d). (d) Eligible taxpayer For purposes of this section, the term eligible taxpayer means any taxpayer, except that— (1) no single household shall include more than 1 eligible taxpayer, (2) married individuals filing a joint return shall be treated as 1 eligible taxpayer, and (3) in the case of individuals not described in paragraph (2) who are members of the same household, only the taxpayer with the highest adjusted gross income for the taxable year shall be treated as an eligible taxpayer. (e) Calendar month For purposes of this section, if a foster child resides in the home of the taxpayer for more than 15 consecutive days of a calendar month but fewer than the total number of days in such calendar month, such foster child shall be treated as residing in the home of the taxpayer for the full calendar month. (f) Portion of credit refundable (1) In general The aggregate credits allowed to a taxpayer under subpart C shall be increased by the lesser of— (A) the credit which would be allowed under this section without regard to this subsection and the limitation under section 26(a) (determined after any reduction of the credit under section 24(a) by reason of section 24(d)), or (B) the amount by which the aggregate amount of credits allowed by this subpart (determined without regard to this subsection, and after any reduction of the credit under section 24(a) by reason of section 24(d)) would increase if the limitation imposed by section 26(a) were increased by the greater of— (i) 15 percent of so much of the taxpayer's earned income (within the meaning of section 32) which is taken into account in computing taxable income for the taxable year as exceeds $3,000, or (ii) in the case of a taxpayer with 3 or more qualifying foster children residing in the home of the taxpayer for all months in the taxable year (without regard to whether the same 3 children reside in the home of the taxpayer for all