Except as provided in subsection (c) of this section and unless expressly provided otherwise by law, an amendment of the Internal Revenue Code that affects the determination of federal adjusted gross income or federal taxable income, does not affect the determination of Maryland taxable income under this title for: any taxable year that begins in the calendar year in which the amendment is enacted; or any taxable year that precedes the calendar year in which the amendment is enacted. Within 60 days after an amendment of the Internal Revenue Code is enacted, the Comptroller shall prepare and submit to the Governor and, subject to § 2–1257 of the State Government Article, the President of the Senate and the Speaker of the House a report that outlines: the changes in the Internal Revenue Code; and the impact of those changes on State revenue and on various classes and types of taxpayers. Subsection (a) of this section does not apply to an amendment of the Internal Revenue Code if the Comptroller determines that the impact of the amendment on State income tax revenue is less than $5,000,000 for: the fiscal year that begins during the calendar year in which the amendment is enacted; or any fiscal year that precedes the calendar year in which the amendment is enacted.