(CNN) Tax day isn't until Monday, but there have already been some surprises for Americans filing their first income tax returns under President Donald Trump's 2017 law.

Let's start with the big one. While most Americans are paying less in taxes overall, many have been startled to find that their refunds have barely changed or are down -- making them feel like they lost, even if they're still coming out ahead.

Below are some other ways to look at who is winning and losing under the law. And please take note: It's possible to both win and lose at the same time.

Winning: Most US taxpayers

The vast majority of American tax filers -- more than 65% -- will see their overall tax burden decrease by at least $100, according to the congressional Joint Committee on Taxation. See page 7 of this helpful analysis

Slightly less than 30% of filers will see very little change in their tax liability and a small percentage, about 6%, will see an increase. These tax rate cuts for individual filers are not permanent like the corporate tax cuts, but they'll be in place until 2025.

But while most Americans got a tax cut, most people don't seem to understand they got one. According to an NBC News/Wall Street Journal poll out this week, only 17% of Americans think they're getting a tax cut while 28% said they will pay more.

Winning: Most rich people

The new tax law's benefits are tilted toward the wealthy, who will generally see greater benefits than other Americans.

largest cuts will go to the people who pay the most in tax, according to the Thelargest cuts will go to the people who pay the most in tax, according to the Tax Policy Center , a think tank, which suggested that tax filers in the 95th to 99th percentile of income -- roughly between $308,000 and $733,000 -- would see the largest benefit as a portion of after-tax income.

Most people in the bottom 20% income-wise will see little or no change in their tax liability, according to that report.

Losing: Some rich people, probably in blue states

About 14% of rich people making more than $1 million will see a tax increase. They're likely to be concentrated in states with high state and local taxes and they possibly have multiple homes. They used to be able to deduct a lot more of their state and local income taxes from their federal returns. Now those deductions are capped at $10,000.

Really winning: Heirs of rich people

The law more than doubled the amount that can pass to family members without triggering the estate tax , from about $5 million to more than $11 million for individuals and $22 million for married couples. That affects a relatively small number of Americans, but it means they'll be able to keep more of an estate.

Still winning: Investors

The rates for capital gains taxes did not change in the tax law and remain lower than the rates for wage income. So people making money primarily off investments will continue to pay less in taxes than people who depend mostly on salary income.

Winning: Trump, maybe, although some other business owners won't win as much

Most small business owners (and a lot of not-so-small business owners) include their profits on personal income tax returns instead of paying as corporations. Trump is presumably among these, although it's impossible to know since he has kept his tax returns from public view.

Under the law, which the IRS clarified in January, certain types of business owners get a 20% tax deduction. Doctors and lawyers lost out on that exemption, however, along with Major League Baseball team owners.

Winning: Red state filers who depend on refunds

According to preliminary data from H&R Block, it is mostly red states, those that voted for Trump in 2016, who are getting the largest bump in tax refunds.

Losing: Blue state filers who depend on refunds

That H&R Block preliminary data shows that every one of the states where refunds are shrinking is blue. Of course, experts say you should aim to have no refund and no tax bill on tax day. But a lot of Americans rely on the refunds as a sort of forced savings plan.

In the preliminary H&R Block data, some of the states with the largest decreases in tax liability are blue states with high state and local taxes, like New Jersey, California and Massachusetts. Filers in these high tax states averaged some of the largest tax cuts. They also saw some of the largest average decreases in refunds.

Losing: People who thought a tax cut would mean a bigger refund

According to preliminary 2018 tax filing season data from H&R Block , one of the nation's largest tax preparers, the average tax filing they've processed so far shows a 24.9% drop in tax liability. But because of the way the IRS changed its paycheck withholding, that cut was spread over the course of the year and refunds, on average, have barely moved.

The government paid $6 billion less in refunds through March 29, according to the IRS, although the average refund, according to its data, is $2,873 and has shrunk less than 1% compared with last year.

Losing: People who aren't getting a refund but maybe thought they would

The government is paying out fewer refunds this year under the new tax law, according to preliminary IRS data on filings through March 29 . There have been 2.2% fewer refunds than last year, according to the IRS, but only 1.4% fewer returns processed.

Winning: People doing their own taxes

There was a 2.3% increase in the number of e-filed tax returns self-prepared by the filer, according to that IRS data from March 29. At more than 358 million, visits to IRS.gov are up more than 10% this year. That said, the new tax law preserves the deduction people can take for hiring an accountant (assuming they are not taking the standard deduction).

Winning: People taking the standard deduction

Taxes should get easier since the standard deduction nearly doubled to $12,200 for individuals and $24,400 for married couples. That means that most Americans will not itemize their tax returns and that caps on state and local tax deductions may not affect as many people as feared.

Losing: Washington, DC, tax filers

The capital is seeing the largest average refund drop, at 6.1%. It is also seeing the smallest decrease in average tax liability, 18% -- which is indeed a cut, but the smallest, on average, in the country.

Winning forever: Corporations

They got a massive rate cut, from 35% to 21%, starting in 2018 that's permanently enshrined in the new law.

Losing: The US Treasury