"I take full responsibility for each act that I pled guilty to, the personal ones to me and those involving the president of the United States of America."
The hearing in New York City before U.S. District Judge William H. Pauley III began just before 11am local time and Cohen was joined in the courtroom by his wife, daughter and son.
Pauley said Cohen's sentence should reflect the competing interests of the Cohen case — punishing those who repeatedly break the law, and rewarding those who cooperate and provide truthful testimony.
"Our democratic institutions depend upon the honesty of our citizenry in dealing with the government," Pauley said, calling his crimes serious, particularly given his profession.
"As a lawyer, Mr. Cohen should have known better. Tax evasion undercuts the government's ability to provide essential services upon which we all depend," the judge said.
"While Mr. Cohen is taking steps to mitigate his criminal conduct by pleading guilty and volunteering useful information to prosecutors, that does not wipe the slate clean.
"Mr. Cohen selected the information he disclosed to the government. This court cannot agree with the defendant's assertion that no jail time is warranted. In fact this court firmly believes that a significant term of imprisonment is fully justified in this highly publicised case to send a message," the judge said.
At the hearing's outset, Pauley settled a minor dispute between Cohen's lawyers and the prosecutors: how Cohen's tax crimes should be counted under federal sentencing guidelines.
Pauley said the government's calculation was correct, and that the sentencing guidelines suggested a prison sentence of as much as five years and three months — but that is only a suggested range, and the judge will hear from both sides before deciding the sentence.
Prosecutors, while advocating for a "substantial term of imprisonment," have said Cohen deserved less than what the guidelines call for because he has been somewhat cooperative, but they noted Cohen never agreed to fully cooperate and tell all that he knew.
The U.S. probation office recommended a sentence of 3½ years.
In a court filing asking for no jail time, Cohen's lawyers wrote that their client's misdeeds were a product of his "fierce loyalty" to Trump and put the wrongdoing squarely at the feet of the president and his close advisers.
Cohen's lawyer, Guy Petrillo, urged the judge to be lenient in light of what he called Cohen's courage and "the remarkable nature and significance" of his decision to cooperate against Trump.
"He knew that the president might shut down the investigation . . . He came forward to offer evidence against the most powerful person in our country," said Petrillo.
He did so not knowing what the result would be, not knowing how the politics would play out," or whether the special counsel investigation of Russian interference in the 2016 election "would even survive."
As a result, Petrillo said, Cohen and his family have faced public outrage and threats.
"This is not a case of standard cooperation," Petrillo said, because the investigation in question is as significant as the Watergate probe into President Nixon 40 years ago.
Petrillo said Cohen is willing to cooperate further with the FBI, and said it was unfair for prosecutors to say he is refusing to discuss other possible crimes he may know about.
"He's ready to do that," said Petrillo. "It's fundamentally unfair for a prosecutor to ask a court to sentence a defendant on hypothetical facts and circumstances."
Petrillo asked the judge to reduce Cohen's sentence, saying the case "calls for a full consideration of mercy."
Cohen's lawyers have said he was in "close and regular contact with White House-based staff and legal counsel" when he prepared his false testimony to Congress about a possible Trump Tower project in Moscow and that he acted at Trump's direction in paying off the women.
Jeannie Rhee, part of special counsel Robert S. Mueller III's prosecution team, told the judge that Cohen "has endeavoured to account for his criminal conduct in numerous ways," providing "credible and reliable information about core Russia-related issues under investigation."
Rhee said she could not go into detail about the ongoing Russia investigation, but said Cohen was "helpful" to the probe. Cohen, she said, was "careful to note what he knows and what he doesn't know . . . Mr. Cohen has sought to tell us the truth, and that is of utmost value to us."
Nicolas Roos, a federal prosecutor in New York, was far more critical of Cohen, saying he "quite brazenly stole millions of dollars in income from the IRS."
Roos urged the judge to give Cohen a significant amount of time in prison, as punishment for having "eroded faith in the electoral process and the rule of law."
The prosecutor urged the judge to send a message with his sentence of Cohen, that "even powerful and privileged individuals cannot violate these laws with impunity."
Trump and his legal team have sought to downplay Cohen's allegations, and the president has said Cohen deserves a "full and complete" sentence.
Trump has denied having the affairs, and this week accused his political opponents of focusing on the campaign finance matter because, the president claimed, they had failed to prove his campaign coordinated with Russia to influence the election.
"Cohen just trying to get his sentence reduced," Trump wrote on Twitter. "WITCH HUNT!"
Cohen has pleaded guilty in two separate cases. One was brought by Mueller over Cohen's lies to Congress. The other was brought by federal prosecutors in New York over tax and bank fraud allegations and campaign finance violations.
The special counsel's office, for its part, seems to view Cohen as a valuable cooperator. Mueller's prosecutors did not recommend any particular punishment in their case, but said he should not serve any additional prison time beyond his sentence in the New York case.
They credited Cohen with providing "useful information" about the ongoing probe of Russian interference in the 2016 election, as well as "relevant information" about his contacts with people connected to the White House between 2017 and 2018.