; and (B) the average number of employees of which was less than 500 full-time equivalent employees (within the meaning of section 4980H of the Internal Revenue Code of 1986) for the calendar year ending with or within the preceding taxable year. (b) Coordination with section 7508A In the case of any postponement or extension by the Secretary of the Treasury (or the Secretary's delegate) under section 7508A of the Internal Revenue Code of 1986 affecting the due date of the required installments under section 6654 of such Code, subsection (a) shall apply only if the due date for the 1st installment under paragraph (1)(B) thereof is later than the due date prescribed for the 1st installment under such postponement or extension. 4. Employee retention credit for employers of employees affected by COVID–19 (a) In general In the case of an eligible employer, there shall be allowed as a credit against the tax imposed by section 3111(a) of the Internal Revenue Code of 1986 or section 3221(a) of such Code for each calendar quarter an amount equal to 50 percent of the qualified wages with respect to each eligible employee of such employer for such taxable year. The amount of qualified wages with respect to any eligible employee which may be taken into account under this subsection by the eligible employer for all calendar quarters during any designated period shall not exceed $7,500. (b) Eligible employer (1) In general The term eligible employer means any employer which— (A) which has less than 500 full-time employees on the first day of the designated period with respect to the employer; and (B) which— (i) conducted an active trade or business in a qualified coronavirus disaster zone and meets the requirements of paragraph (2)(A); or (ii) meets the requirement of paragraph (2)(B). (2) Requirements (A) In general An employer meets the requirements of this subparagraph if— (i) the employer is required to close as a result of a directive by a Federal, State, or local authority