; and (4) the probability of the imposition of duties on the importation of such drug. . 4. Priority medicine production credit (a) In general Subpart D of part IV of subchapter A of chapter 1 of the Internal Revenue Code of 1986 is amended by adding at the end the following new section: 45U. Priority medicine production credit (a) General Rule For purposes of section 38, the priority medicine production credit determined under this section for the taxable year is an amount equal to 50 percent of the qualified priority medicine expenses for the taxable year. (b) Qualified priority medicine expenses (1) Qualified priority medicine expenses The term qualified priority medicine expenses means direct and indirect costs paid or incurred by the taxpayer during the taxable year for the production of priority medicines. (2) Priority medicines For purposes of this section, a priority medicine is a medicine that was included, within the 5 calendar years immediately preceding the taxable year, on the list developed and published by the Secretary of Health and Human Services pursuant to section 2804(d) of the Public Health Service Act. (3) Coordination with section 263A (A) Coordination with section 263A In applying section 263A, indirect costs shall be allocated between the production of priority medicines and the production of other medicines based on the ratio in which the number of doses of the priority medicines produced in the taxable year bears to the total number of doses of all medicines produced by the taxpayer in that taxable year to which the expense is attributable. (B) Regulations and guidance The Secretary shall by regulation or other guidance prescribe rules for the proper allocation of indirect costs described in subparagraph (A). . (b) Credit allowed as business credit Section 38(b) of the Internal Revenue Code of 1986 (relating to current year business credit) is amended by striking plus at the end of paragraph (32), by striking the period at the end of paragraph (33) and inserting , plus , and adding at