REUTERS/Jonathan Ernst

The average federal tax rate plummeted to 11.3% for nearly 400 of America's largest corporations in 2018, just over half of the lowered official rate that President Trump established under the 2017 GOP tax law, according to a new study published Monday.

The analysis also suggested that the average rate was the lowest for corporations in four decades.

The Institute on Taxation and Economic Policy found corporations took advantage of various tax breaks, deductions, and loopholes that the law introduced in order to significantly cut the size of their federal tax bills from the 21% rate.

Roughly 91 Fortune 500 companies paid no federal taxes at all, despite generating $101 billion in profit all together, the report said.

The study is likely to magnify criticism of the 2017 tax law as a windfall for the biggest corporations.

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The average federal tax rate plummeted to 11.3% for nearly 400 of America's largest corporations in 2018. That's just over half the lowered official rate that President Trump established under the 2017 GOP tax law, according to a new study published Monday.

The analysis from the Institute on Taxation and Economic Policy, a left-leaning think-tank, examined the federal taxes that 379 profitable companies in the Fortune 500 paid last year as the Tax Cuts and Jobs Act took effect.

It found corporations took advantage of various tax breaks, deductions and loopholes that the law introduced to significantly cut the size of their federal tax bills from the 21% rate.

The law "supercharged" some by changing depreciation rules and allowing companies to instantly write off capital investments immediately instead of waiting for the assets to wear out, the study said. It also allowed executives to deduct the value of their stock options from compensation packages.

The analysis also suggested that the 11.3% average rate was the lowest for corporations in four decades. Around 91 Fortune 500 companies paid no federal taxes at all, despite generating $101 billion in profit all together, the report said. Had they paid the full tax rate, corporations would have collectively owed $73 billion more.

Some of the nation's best-known companies paid a zero percent tax rate. Household names among them include Amazon, FedEx, Netflix, General Motors, and Starbucks.

The ITEP report called for a minimum tax rate to be set on corporations to boost the amount of money paid to the federal government every year.

The study is likely to magnify criticism of the 2017 tax law as a windfall for the biggest corporations. Republicans argued it would pay for itself through increased business investment resulting in dramatic economic growth.

But Democrats say that corporations and stockholders reaped most of the law's rewards, and experts say it failed to deliver long-term economic benefits.

The law did contain benefits for individuals and families, but they're set to expire while the reduced corporate tax rate is locked in.

Six Democratic presidential candidates are calling to restore the 35% federal tax rate for corporations that existed before the law's passage, including Sens. Bernie Sanders and Elizabeth Warren, according to the Washington Post. Most have proposed raising it.

Corporate tax revenue dropped steeply from $297 billion in 2017 to $204 billion in 2018, helping to reduce the US tax burden to one of the lowest among major global economies.

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