Donald Trump is the first president in almost 40 years to not release his tax returns, which has people wondering: What's in them?
Trump promised to release them during his campaign, but he has yet to do so, citing an ongoing audit by the Internal Revenue Service.
"I'm under a routine audit and it'll be released, and as soon as the audit is finished it will be released," Trump said at the first debate in September.
An audit doesn't legally stop a person from releasing tax returns, though.
WHY HE'S PROMISING IT
Trump was called on repeatedly to release his tax returns throughout the election.
While not required by law, all but one major party nominee over the last 40 years has released tax returns for the prior year. Republican President Gerald Ford did not release a tax return, either.
Trump's team argued during the campaign that his release of financial disclosures were most than sufficient, but that isn't true.
Experts told PolitiFact in 2016 that releasing tax returns would offer valuable details on his tax rate, the types of taxes he paid, and his charitable giving, as well as a better idea of his income-producing assets.
WHAT'S STANDING IN HIS WAY
While Trump has made it seem like they are factors standing in his way, experts have labeled those reasons as excuses and have questioned his lawyers' rationale.
There is no law that stops a person from releasing tax returns while under audit. Richard Nixon released his tax returns in the middle of an audit a year after being re-elected.
Edward McCaffrey, a tax law professor at the University of Southern California, wrote a column on CNN in August 2016 dissecting Trump's excuses one by one and ultimately concluded none were valid.
McCaffrey told PolitiFact in November the reason Trump hasn't released his tax returns comes down to not wanting other people to help the IRS see issues that might cost Trump money.
In March 2016, Trump's attorneys wrote a letter explaining why they have advised Trump to not release his returns. They cite Trump's ownership in over 500 companies and said his tax returns are unusually complex, which is why they have been under examination.
Given that being under audit doesn't stop someone from releasing his returns, Brian Galle, a tax law professor at Georgetown University, questions how "my attorneys told me not to" is an acceptable excuse.
"It is tantamount to saying, in essence, that there is something incriminating that the official does not want uncovered," Galle said.