September 10, 2025
WASHINGTON, D.C. — U.S. Senators Angus King (I-ME) and Elizabeth Warren (D-MA) are leading a bicameral group of their colleagues in a letter urging Treasury Secretary and Acting Internal Revenue Service (IRS) Commissioner Scott Bessent to strongly implement a tax law passed by Congress that requires the largest American corporations to pay their fair share in taxes. The corporate alternative minimum tax (CAMT) requires that companies reporting over $1 billion in profits to their shareholders must pay at least 15 percent of those profits in taxes, applying to approximately 150 of America’s wealthiest corporations.
From 2018 to 2020, 39 Fortune 500 companies generating $122 billion in profit paid $0 in federal income tax. One of the most profitable companies in the United States secured a 4.3 percent effective tax rate on its $43.4 billion income during the same period, less than one-third of the rate paid by the average American taxpayer. The CAMT, which was included as a provision in the Inflation Reduction Act (IRA), imposed a 15 percent minimum tax based on financial income reported to investors and creditors for corporations earing over $1 billion beginning in tax year 2023. However, as of recent under the Trump Administration, Treasury and the IRS have started to loosen certain requirements to help fewer corporations become subject to the tax, further eroding the Congressional intent of the law.
“We write to express our concern about the Trump Administration's recent publication of multiple interim guidance notices that create new loopholes in the corporate alternative minimum tax (CAMT) for the largest and wealthiest corporations. These notices will allow major corporations to circumvent the law by using accounting trickery to pay zero taxes on their massive profits,” the lawmakers began.
“Prior to CAMT’s enactment, corporations worth billions of dollars would routinely pay little or no federal income tax. From 2018 to 2020, 39 Fortune 500 companies generating $122 billion in profit and paid $0 in federal income tax. One of the most profitable companies in the United States secured a 4.3 percent effective tax rate on its $43.4 billion income during the same period, less than one-third of the rate paid by the average American taxpayer,” wrote the lawmakers.
The lawmakers continued, “The Trump Administration has announced its intent to completely redo the 2024 proposed CAMT regulations, signaling openness to making even more changes and delaying a final regulation indefinitely. In combination, these actions indicate that under President Trump, the IRS is at best delaying the full implementation of CAMT to allow the largest corporations to avoid paying taxes, and at worst abandoning its legal responsibility to administer and enforce CAMT altogether.”
“CAMT is the law of the land, passed by Congress with the strong support of the American people and largely left in place as President Trump and the Republican Congress rewrote the nation’s tax laws earlier this year. The Administration is required to faithfully and punctually implement CAMT consistent with Congressional intent,” the lawmakers concluded.
The letter was also signed by Senators John Hickenlooper (D-CO), Sheldon Whitehouse (D-RI) and Ed Markey (D-MA), as well as Representative Don Beyer (D-VA).
A copy of the letter can be found here, and is included in full below:
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Dear Secretary Bessent:
We write to express our concern about the Trump Administration's recent publication of multiple interim guidance notices that create new loopholes in the corporate alternative minimum tax (CAMT) for the largest and wealthiest corporations. These notices will allow major corporations to circumvent the law by using accounting trickery to pay zero taxes on their massive profits.
Prior to CAMT’s enactment, corporations worth billions of dollars would routinely pay little or no federal income tax. From 2018 to 2020, 39 Fortune 500 companies generating $122 billion in profit and paid $0 in federal income tax. One of the most profitable companies in the United States secured a 4.3 percent effective tax rate on its $43.4 billion income during the same period, less than one-third of the rate paid by the average American taxpayer.
Congress passed the corporate alternative minimum tax as part of the Inflation Reduction Act to put an end to this chicanery. CAMT requires that companies reporting over $1 billion in profits to their shareholders must pay at least 15 percent of those profits in taxes, applying to approximately 150 of America’s wealthiest corporations.
But since CAMT became the law of the land, Congressional Republicans have been doing everything they can to get rid of it, including introducing a law to repeal the CAMT just six weeks after it was enacted. Accountable.US reported that large financial firms and industry groups have also spent more than $1 million lobbying Congress on the CAMT during the first half of 2023 alone. The oil and gas industry secured a carveout from CAMT in the One Big Beautiful Bill Act (OBBBA). And now, after failing to repeal CAMT entirely in the OBBBA, the Trump Administration is attempting to further erode the CAMT through the Internal Revenue Service’s (IRS) two new interim guidance notices. These notices weaken CAMT under the cover of bureaucratic rulemaking and give the largest and wealthiest corporations yet another get-out-of-paying-taxes-free card.
Most troubling, Notice 2025-27, issued this June, allows companies to avoid CAMT if their income—under a simplified accounting method—is below $800 million. The Biden Administration previously set the safe harbor threshold precisely at $500 million in its proposed CAMT rule after calculating that a higher safe harbor threshold would risk exempting corporations that should be subject to CAMT under statute. Now, less than nine months later and with zero justification, this new guidance summarily asserts that an $800 million safe harbor will not run that risk. We are seriously concerned that this cursory loosening of CAMT enforcement will simply allow more wealthy corporations to avoid paying their legally owed share.
Further, this notice also indicates future potential erosion of the CAMT tax base by stating that Treasury and the IRS will reconsider the treatment of unrealized capital gains. This signals a possible reversal of the Biden Administration’s decision to reject industry requests to exempt unrealized capital gains from adjusted financial statement income (AFSI), laying groundwork for an even weaker final rule.
Notice 2025-28, issued in July, introduces a number of additional methods for calculating a corporate partner’s distributive share of partnership AFSI, expanding taxpayer discretion. Though the guidance is framed as simplifying the application of CAMT to partnerships, it creates additional complexity for tax administrators and risks enabling gaming and inconsistent outcomes across similarly situated taxpayers.
The Trump Administration has announced its intent to completely redo the 2024 proposed CAMT regulations, signaling openness to making even more changes and delaying a final regulation indefinitely. In combination, these actions indicate that under President Trump, the IRS is at best delaying the full implementation of CAMT to allow the largest corporations to avoid paying taxes, and at worst abandoning its legal responsibility to administer and enforce CAMT altogether.
CAMT is the law of the land, passed by Congress with the strong support of the American people16 and largely left in place as President Trump and the Republican Congress rewrote the nation’s tax laws earlier this year. The Administration is required to faithfully and punctually implement CAMT consistent with Congressional intent. Accordingly, we urge the IRS to rescind Notice 2025-27 and Notice 2025-28 and finalize the Biden Administration’s proposed CAMT regulations without delay, and request that you respond to the following questions in writing by September X, 2025:
Thank you for your attention to this important matter.
Sincerely,
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