New York City Mayor Zohran Mamdani suffered a significant courtroom setback Monday after a judge temporarily blocked key parts of his administration’s controversial new tax rollout targeting multimillion-dollar second homes.
The decision represents an early victory for homeowners challenging how City Hall implemented the new pied-à-terre surcharge. It also puts renewed attention on property taxes, homeowner privacy and government accountability in one of America’s most expensive real estate markets.
Judge Wayne Ozzi issued a temporary restraining order preventing the city from moving forward with portions of the disputed process.
The order also requires City Hall to take down a supplemental property roll that reportedly disclosed names, addresses and property values connected to more than 900,000 New York City homeowners.
While the underlying tax remains the subject of an ongoing legal fight, the judge found enough problems with the rollout to temporarily intervene.
Judge Blocks Key Parts of New York City Tax Rollout
The dispute centers on New York City’s pied-à-terre surcharge, which targets second homes valued at more than $5 million.
Under the judge’s order, the city is restricted from imposing, assessing or collecting the surcharge against homeowners identified through the disputed supplemental property roll without first completing the individualized determination required under state tax law.
The ruling also prevents the city from enforcing certain deadlines against affected homeowners while the legal challenge proceeds.
Attorney Randy Mastro, representing the homeowners who sued the city, argued that the administration put the process backward.
“The city screwed this up… got it wrong… stop the train and make them do it over,” Mastro told the court.
His argument was straightforward: City Hall should first determine whether a multimillion-dollar property actually qualifies as a second residence before treating its owner as potentially subject to the additional tax.
Instead, according to the lawsuit, large numbers of homeowners received notices and were left trying to establish that the properties in question were actually their primary residences.
“The city is to bear the burden,” Mastro argued.
He accused officials of failing to adequately review information already available to them before sending notices.
“They didn’t do their homework,” he said.
More Than 900,000 Homeowners Listed
The controversy extends beyond taxes.
The administration has also faced criticism over a supplemental property roll containing information associated with more than 900,000 New York City homeowners.
Mastro argued that publishing names, addresses and property values unnecessarily exposed residents and created widespread confusion.
“This is ludicrous. It is not right,” he told the court.
Mastro characterized the publication as effectively “doxx[ing]” homeowners, a description that underscored the privacy concerns at the center of the dispute.
After the ruling, he called the decision “a very good day for all New York City homeowners.”
According to Mastro, some residents received letters suggesting that they could be subject to the surcharge even though they lived full time in the properties.
He argued those homeowners should never have been forced to navigate an exemption process in the first place.
“That’s a pretty shocking thing that happened,” Mastro said.
Homeowners Say City Hall Got It Wrong
Three New York City homeowners filed the lawsuit.
Their challenge is important because they are not asking the court to strike down the pied-à-terre surcharge itself.
Instead, they are challenging the way Mamdani’s administration implemented it.
The homeowners allege that their primary residences were incorrectly identified as properties potentially subject to the surcharge. They also contend that officials failed to make the individualized initial determination required under state law before sending notices.
Their attorneys argue that this improperly shifted responsibility from the government to property owners, forcing residents to prove they did not owe the tax.
One plaintiff, Simon Hedley, eventually obtained an exemption after providing tax information.
Mastro argued that Hedley’s experience showed why the city could have conducted more extensive checks before sending the notices.
“Was it negligence, was it laziness?” he asked in court.
City Hall Defends the New Tax Process
New York City attorneys defended the administration’s actions and warned that stopping the process could create its own problems.
Attorney Steven Banks argued that freezing the rollout could interfere with deadlines and potentially hurt taxpayers attempting to secure exemptions.
The city maintained that keeping the supplemental property roll in place would preserve the existing process while allowing homeowners additional time to determine whether they qualified for an exemption.
The courtroom exchanges became heated.
When Mastro attempted to interrupt Banks during his argument, Banks responded, “Say nothing while I’m speaking.”
The attorneys also clashed over Mastro’s use of the word “terrorizing” to describe how some homeowners allegedly felt after receiving the notices.
Banks objected to the terminology, particularly in connection with an administration led by New York City’s first Muslim mayor.
“That’s not terrorism,” Banks said. “It happens to be acting in accordance with law.”
Mastro later clarified that he was describing homeowners’ perception of receiving government notices telling them their properties could be subject to an additional tax.
He continued criticizing the rollout, describing different elements of the process as “extraordinary,” “bizarre” and “ludicrous.”
Mastro told the court that “thousands of New Yorkers are on edge.”
Judge Finds City May Have Failed to Follow Proper Process
Ozzi ultimately granted temporary relief to the homeowners.
The judge found that the notices could cause irreparable harm and determined that the responsibility for making the initial eligibility determination rested with the city — not individual property owners.
He also concluded that the plaintiffs were likely to succeed on the merits because of apparent problems with the city’s implementation.
That does not mean the homeowners have won the entire case.
A temporary restraining order is an interim measure, and the legality of the underlying surcharge remains unresolved.
But the ruling gives the homeowners an important early victory and forces the Mamdani administration to defend its procedures as the litigation moves forward.
Ozzi acknowledged that the court could not undo notices already mailed to residents, but said further problems could be prevented.
The judge also found that the city had not performed adequate due diligence before moving forward.
Mamdani Administration Announces Appeal
City Hall quickly pushed back against the decision.
Mayor’s office spokesperson Matt Rauschenbach said City Hall opposes the judge’s ruling but continues to stand behind the pied-à-terre surcharge and its ability to administer the tax properly and equitably.
The administration maintains that wealthy property owners with expensive second homes should contribute additional money toward New York City services.
“This surcharge asks those who own second homes valued at $5 million or more to contribute their fair share to the city they benefit from,” Rauschenbach said.
The mayor’s office said the city Law Department would immediately appeal the ruling.
According to the administration, that appeal will stay the order, allowing officials to continue implementing the surcharge while the legal battle unfolds.
Mamdani Refuses to Back Down
Mamdani had already made clear before the ruling that he was prepared to defend the policy.
The mayor even took a public shot at Mastro over the attorney’s repeated legal challenges involving his administration.
Mamdani joked that lawsuits from Randy Mastro against his administration have become almost as predictable in New York City as death and taxes.
Mamdani maintains that revenue generated by the surcharge on second homes worth more than $5 million can help fund city priorities, including schools, public safety and other municipal services.
Asked whether he regretted the controversial rollout, Mamdani continued to defend his administration.
“With any new tax, there are more questions than there are answers,” he said.
The mayor also emphasized that only a relatively small percentage of New Yorkers are expected to actually pay the surcharge.
According to Mamdani, approximately 17,000 homeowners could potentially be affected in a city of roughly 8.5 million residents.
His administration has also extended the deadline for homeowners seeking exemptions.
Why the Ruling Matters for New York Homeowners
Although the surcharge specifically targets multimillion-dollar second homes, the lawsuit raises a much broader question that could resonate with homeowners far beyond New York City:
Who carries the burden when the government believes a taxpayer owes additional money?
The homeowners challenging Mamdani’s administration argue that government officials must first establish that a property qualifies for the tax rather than forcing residents to prove that it does not.
That issue touches on broader concerns surrounding property rights, government bureaucracy, privacy and taxpayer protections.
For conservatives already skeptical of New York City’s approach to taxation and spending, the controversy is likely to provide another example of why government agencies should face strict requirements before imposing additional financial burdens on property owners.
Supporters of the surcharge see the issue differently. They argue that owners wealthy enough to maintain second homes valued above $5 million can afford to contribute more toward the city services from which they benefit.
The courts will now determine whether City Hall followed the law when attempting to put that policy into practice.
What Happens Next in Mamdani Tax Battle
The legal fight is moving quickly.
Ozzi ordered the defense to submit its order to show cause by Aug. 24, while the plaintiffs are expected to respond by Aug. 27.
Oral arguments on the merits are scheduled for Aug. 31.
That means Monday’s ruling is unlikely to be the final word.
For now, however, homeowners challenging the Mamdani administration have secured an important early courtroom victory — while City Hall faces growing scrutiny over how its new luxury property tax was rolled out.
The next round could determine whether the administration is allowed to proceed as planned or whether New York City will be forced to substantially change how it identifies and taxes owners of high-value second homes.