The Times did not look at his federal return. It obtained one page of his New York State resident income tax return as well as the first page of New Jersey and Connecticut nonresident returns.
CNN has not independently verified the documents' authenticity, but Trump's campaign has not challenged any of the facts reported by The Times.
Mounting questions about Trump's businesses and finances are set to test Republicans' loyalty to the party's nominee. And they will test Trump's temperament as well, the week before his second debate with Hillary Clinton.
Here are six questions about Trump's taxes and the political fallout:
Did Trump pay income taxes?
We still don't know.
The bottom line: Unless and until he releases his personal income tax returns, as every other presidential nominee since 1976 has, there's no way to verify what Trump has or hasn't paid.
However, Trump's $916 million loss in 1995 -- around the time his Atlantic City casinos were going bust -- could be spread out over a total of 18 years to offset the taxable profits he earned from other businesses.
It's possible Trump lost money other years, as well, which could be used similarly. And he has a slew of tax breaks available to real estate developers
Trump's steadfast refusal to release his tax returns -- the last 12 years' worth are under "routine audit," he's said repeatedly -- make it impossible to know what he's paid.
What's the immediate political damage?
Trump has just five weeks left to Election Day -- and the next several days are all but certain to be dominated by questions about whether he pays taxes.
Any hope Trump had of dodging and deflecting on the issue through November 8 is now gone.
Even more troubling: He just spent a week feuding with a former Latina Miss Universe who he had publicly ridiculed as "Miss Piggy" and "Miss Housekeeping" 20 years ago -- and who he continued insisting was overweight last week, rather than dropping the issue.
At this stage in the tightly contested race, Trump's momentum has stalled and time is an increasingly precious resource. Unless he is suddenly willing to share much more information about his taxes, he'll have squandered two important weeks as early voting is underway in several key states.
Is 'genius' very smart?
The messaging out of Trump Tower has been clear: If Trump didn't pay federal income taxes, it makes him a "genius."
It was the buzzword coming from Trump's top surrogates on the Sunday shows.
"The reality is, this is part of our tax code. The man's a genius. He knows how to operate the tax code to the benefit of the people he's serving," former New York City mayor Rudy Giuliani told CNN's Jake Tapper on "State of the Union."
"There's no one who's shown more genius in their way to maneuver around the tax code and to rightfully use the laws to do that," New Jersey Gov. Chris Christie said on "Fox News Sunday."
But labeling Trump a "genius" when so many questions remain unanswered is politically problematic because it implies that Trump in fact did not pay taxes. And if he's a genius for not paying income taxes, what does that make everybody who does?
Will this hurt Trump in the Rust Belt?
The case for Trump has long been that hard-working Americans -- particularly in the Rust Belt -- have been unfairly hammered by outside forces like immigration and globalization.
By refusing to directly address the questions raised by The New York Times report, Trump's campaign so far has left open the possibility that those workers for years have paid more in federal income taxes than Trump, despite his vast wealth.
If the revelations on Trump's taxes leave Trump looking like a beneficiary of the status quo in Washington, it could become harder for him to sell himself as an outsider in states like Pennsylvania and Ohio, where he desperately needs wins.
There is evidence that a majority of voters believe it is important that presidential candidates release their tax records.
In a Monmouth University poll last month, 62% of those asked thought it was very important or somewhat important for candidates to show their tax records.
Will Trump face more pressure to release his tax returns?
Yes -- particularly now that new questions have been raised.
That pressure could be amplified by members of Trump's own party. Congressional Republicans will be asked a new round of questions about Trump's taxes, and some could call on him to release his returns.
It's also sure to be a hot topic in the vice presidential debate, pitting Trump's running mate Mike Pence against Virginia Sen. Tim Kaine on Tuesday night.
Add this to the list of questions Trump has left unanswered: Has he paid income taxes? Why did he suddenly decide President Barack Obama was born in the United States? What keeps him from dropping distracting personal feuds with people like Alicia Machado and Rosie O'Donnell?
In each public appearance and interview this week, Trump will be asked questions related to his taxes. He will likely answer by bashing the media and pivoting to attacks on Clinton -- which will only perpetuate the questions.
Will Trump react by attacking Clinton?
Over the course of the 2016 campaign, Trump has repeatedly demonstrated that he reacts to personal slights by lashing out angrily -- often with attacks on individuals that come at a political cost, such as his criticism of Indiana-born Judge Gonzalo Curiel's Mexican heritage and the Gold Star Khan family.
The tax revelations won't just create new pressure for Trump to release his returns, they'll raise questions about the credibility of Trump's claims he has created a "great company."
Trump offered a glimpse of the bare-knuckled style he's returning to Saturday night in Pennsylvania, as news of his $916 million loss in 1995 broke.
He said Clinton "could be crazy" and lacks the "stamina" to be president -- even imitating Clinton stumbling into her car while leaving a 9/11 ceremony last month. And he questioned, with no evidence, whether the Democratic nominee is "loyal" to her husband.
"I don't even think she's loyal to Bill, if you want to know the truth. And really folks, really, why should she be?" Trump said Saturday, apparently calling into question Clinton's marital fidelity to her husband -- without evidence -- in his most direct terms yet.
He willl campaign in northern Virginia and Colorado on Monday, followed by Arizona on Tuesday, in what will be the first tests of his temperament and handling of tax return questions.