means the following: (A) The taxes imposed under section 3111(a) of the Internal Revenue Code of 1986. (B) So much of the taxes imposed under section 3221(a) of such Code as are attributable to the rate in effect under section 3111(a) of such Code. (h) Regulations and guidance The Secretary of the Treasury (or the Secretary's delegate) may prescribe such regulations and other guidance as may be appropriate or necessary to carry out the purposes of this section. (i) Termination This section shall not apply to any costs paid or incurred in taxable years beginning after December 31, 2023. 3. Improvements to employee retention tax credit (a) Increase in credit percentage Section 2301(a) of the CARES Act ( Public Law 116–136 ) is amended by striking 50 percent and inserting 80 percent . (b) Increase in per employee limitation Section 2301(b)(1) of the CARES Act is amended by striking for all calendar quarters shall not exceed $10,000. and inserting shall not exceed— (A) $15,000 in any calendar quarter, and (B) $45,000 in the aggregate for all calendar quarters. . (c) Modification of threshold for treatment as a large employer (1) In general Section 2301(c)(3)(A) of the CARES Act is amended— (A) by striking for which the average number of full-time employees (within the meaning of section 4980H of the Internal Revenue Code of 1986) employed by such eligible employer during 2019 was greater than 100 in clause (i) and inserting which is a large employer , and (B) by striking for which the average number of full-time employees (within the meaning of section 4980H of the Internal Revenue Code of 1986) employed by such eligible employer during 2019 was not greater than 100 in clause (ii) and inserting which is not a large employer . (2) Large employer defined Section 2301(c) of the CARES Act is amended by redesignating paragraph (6) as paragraph (7) and by inserting after paragraph (5) the following new paragraph: (6) Large employer The term large employer means any eligible employer if— (A) the average number of full-time