Republicans’ new tax law delivered for Amazon .com, which saw its U.S. corporate income taxes shrink by more than half in 2025 while its profits climbed.

The company’s current U.S. taxes, an accounting measure of taxes incurred last year, declined to $1.2 billion from $9 billion, according to a securities filing released Friday. Meanwhile, Amazon’s pretax U.S. profit increased by 44.5%, to $89.5 billion. On a cash basis, the company paid $2.8 billion in federal income taxes last year after paying more than $7 billion in each of the prior two years.

The figures offer one of the clearest examples yet of how the largest U.S. companies are benefiting from the tax cuts, which are also boosting individual tax refunds this year.

The law, signed by President Trump in July, made two major changes that quickly helped Amazon and other corporations.

First, the law allowed companies to claim immediate deductions for certain capital investments rather than spreading those write-offs over several years. Like other tech companies, Amazon has been investing heavily in data centers, and much of the equipment inside would qualify for the immediate deductions. The company said it spent $340 billion in the U.S. last year, including operating costs and capital investments.

Second, the new law reversed a piece of the prior Republican tax law that companies had been complaining about. The old law required them to spread out deductions for research, starting in 2022. The new law permits immediate deductions for new domestic research and lets companies accelerate previously delayed deductions.

“Congress made changes to the tax code to encourage greater investment in the American economy, its innovation, and its workers—all areas where Amazon has long been a leader,” the company said Friday . “Due to Amazon’s unprecedented U.S. investments, our tax bill this year reflects those changes.”

Other large companies have been reporting benefits from the new law. In a filing this week, Google parent Alphabet said its federal and state current tax expense declined by 36.6% while its pretax domestic profit rose by 32.9%.

Amazon lobbied on the tax bill and was involved in pushing for the changes to the research deduction.

In its earnings report Thursday, the company said it expected to make capital expenditures of $200 billion in 2026, as it accelerates spending in artificial-intelligence projects. The company is increasing AI-related spending, while cutting costs,   laying off another 16,000 employees and closing underperforming businesses .

For accounting purposes, Amazon’s global effective tax rate actually went up in 2025, increasing to 19.6% from 13.5% in 2024. That is in part because the company’s research tax credits declined slightly while profits increased.

The accounting rules that are used to compute the effective tax rate include both current taxes and deferred taxes, so accelerating deductions into 2025 doesn’t change that rate. Amazon recorded $11.1 billion in deferred U.S. taxes along with its $1.2 billion in current taxes. The company said it expects the tax law to have a similar effect on its 2026 tax payments.

“Deducting our costs more quickly provides a short-run benefit but this policy ultimately doesn’t change the amount of tax we pay. It just changes the timing of our tax payments,” the company statement said.

At times over the past decade, Amazon has reported little or no current U.S. taxes while reporting large profits, a pattern that drew the attention of members of Congress, particularly Democrats. In 2022, under President Joe Biden , they created a new corporate minimum tax aimed at ensuring that companies pay at least 15%.

But that law was also written to retain incentives for capital investment. And while companies such as Meta Platforms and Qualcomm have warned that they are getting hit by that tax, Amazon’s filing don’t suggest much effect from it.

Worldwide, Amazon paid $8.3 billion in cash income taxes last year, down from the prior two years. That total includes the federal taxes plus more than $2 billion to U.S. state and local governments and more than $3 billion to foreign governments.

Write to Richard Rubin at richard.rubin@wsj.com