; unrelated person Rules similar to the rules of paragraphs (2) and (3) of section 45X(a) shall apply. (3) Disallowance of credit The credit under this subsection shall not be allowed to any taxpayer which, at any time during the taxable year, was a foreign entity of concern (as defined in section 9901(8) of the William M. (Mac) Thornberry National Defense Authorization Act for Fiscal Year 2021 ( 15 U.S.C. 4651 )). (b) Credit amount (1) In general Subject to paragraph (4), the amount determined under this subsection with respect to any eligible component shall be an amount equal to— (A) the value added to such component by the taxpayer, multiplied by (B) the base credit percentage. (2) Value added The value added to a component by a taxpayer is an amount equal to— (A) the gross receipts received by the taxpayer from the sale of the eligible component, minus (B) the cost of eligible components purchased from an unrelated person in connection with the production of the component by the taxpayer. (3) Base credit percentage (A) In general Except as provided in subparagraphs (B) and (C), the base credit percentage shall be 30 percent. (B) Increased base credit percentage for certain eligible components The base credit percentage shall be 35 percent in the case of the final production of— (i) a drug substance, (ii) a drug product, or (iii) a biological product. (C) Domestic content bonus credit (i) In general In the case of an eligible component which contains domestic content, the base credit percentage determined under this paragraph (determined without regard to this subparagraph) shall be increased by an amount equal to— (I) the domestic content percentage, multiplied by (II) 0.20. (ii) Domestic content percentage For purposes of this paragraph, the term domestic content percentage means the percentage of the total cost of the bill of materials of the eligible component that is attributable to materials and components that were produced in the United States. (iii) Documentation rules (I) Recordkeeping No domestic