The act introduces a new 15% corporate alternative minimum tax (AMT) on the adjusted financial statement income of certain large corporations with annual income over $1 billion, effective for tax years beginning after Dec. 31, 2022. This provision aims to ensure that highly profitable corporations pay a minimum level of tax. Additionally, the act includes a 1% excise tax on stock buybacks by publicly traded corporations, effective for repurchases after Dec. 31, 2022. Reference: [26 U.S. Code § 59A](https://www.law.cornell.edu/uscode/text/26/59A) (Corporate Alternative Minimum Tax), [26 U.S. Code § 4501](https://www.law.cornell.edu/uscode/text/26/4501) (Stock Buyback Excise Tax)