What Businesses Should Watch This Fall

by David Zaiken

September is proving to be an unusually active month in Washington and beyond, with important developments in tax, trade and international negotiations. While many details remain unsettled, the direction of these debates could affect year-end planning, international operations and import costs for U.S. businesses. Here are four areas to keep on your radar.

1) Congress and the September 30 Deadline

Lawmakers face a September 30 deadline to keep the federal government funded. A short-term “continuing resolution” is widely expected, but negotiations will likely push major tax decisions into a year-end package. Some Democratic senators are signaling they will only support a deal if it includes an extension of Affordable Care Act premium tax credits that expire at the end of 2025.

Why it matters: Year-end legislation could once again become the vehicle for tax changes, possibly affecting credits, deductions or compliance obligations that impact planning for 2025 and beyond.

2) International Tax Policy: Section 899 Back in Play?

On September 9, members of the House Ways & Means Committee met with Treasury officials to discuss implementation of the One Big Beautiful Bill Act (OBBBA). Reports suggest Treasury could be open to reviving Internal Revenue Code Section 899, a retaliatory tax regime, if other countries fail to honor the G7 commitment to exempt U.S.-parented groups from the Undertaxed Profits Rule and Income Inclusion Rule. The OECD is currently working on adjustments to the global minimum tax framework (BEPS Pillar Two) that could ease U.S. concerns.

Why it matters: For U.S. multinational groups, the possibility of retaliatory measures adds another layer of uncertainty to global tax planning. Companies should monitor how partner countries respond to the G7 agreement and whether Congress moves to act.

3) Corporate AMT Guidance Under Scrutiny

Two recent IRS notices — 2025-27 and 2025-28 — have drawn criticism from lawmakers who say the guidance could erode the corporate alternative minimum tax (CAMT). Notice 2025-27 raises the safe harbor threshold for applicable corporations from $500 million to $800 million under a simplified method, while Notice 2025-28 adds complexity for companies with partnership income.

Why it matters: If these rules stand, some companies may escape CAMT liability while others face added compliance burdens. Guidance could shift again, so businesses near the thresholds should evaluate exposure and modeling assumptions carefully.

4) Supreme Court Takes Up Reciprocal Tariffs

The Supreme Court has agreed to hear a challenge to President Trump’s Reciprocal Tariff Policy, with oral arguments scheduled for early November. A lower court recently ruled that certain tariffs exceeded presidential authority under the International Emergency Economic Powers Act, but those duties remain in effect pending the high court’s decision. Other duties, including Section 301 tariffs on China and Section 232 tariffs on steel and aluminum, are unaffected.

Why it matters: Importers should prepare for potential changes in tariff exposure, but recognize that many existing duties remain firmly in place regardless of the Supreme Court’s decision.

Things Continue to Shift

Taken together, these developments highlight the shifting ground businesses face in international tax and trade. While the final outcomes will unfold over the next few months, it’s not too early to model scenarios and consider year-end planning adjustments.

The convergence of global minimum tax negotiations, domestic CAMT guidance and tariff litigation means businesses need to prepare for multiple moving parts this fall. Staying proactive now reduces the risk of costly surprises later.

If your company has cross-border operations, partnership income or exposure to U.S. tariffs, now is the time to review your position. Preparing for and strategic thinking as these items evolve continues to be of key importance. Contact our International Tax team to discuss how these developments could affect you.