The legal challenge to New York City's rent freeze that was anticipated for weeks has now arrived in court. Six landlords filed an Article 78 petition in New York Supreme Court on July 22 seeking to overturn the Rent Guidelines Board's June 25 decision to freeze rents for all one- and two-year stabilized leases commencing between October 1, 2026 and September 30, 2027. The petition asks the court to annul the vote, send the issue back to the board for reconsideration, and keep the prior RGB Order #57 increases of 3% for one-year leases and 4.5% for two-year leases in place until the board reaches a new decision. The judge has ordered the city to present its defense in September.

For the roughly one million stabilized apartments and 2.4 million tenants affected by the freeze, and for the building owners managing those units, this lawsuit is not a sideshow. It is the primary legal process that will determine whether the October 1 freeze takes effect as currently structured — or whether a court intervenes before that date. Understanding what the landlords are actually arguing, why this case differs from prior failed freeze challenges, and what each possible outcome means in practice is essential for anyone with stabilized units in their portfolio or their life.

What the Lawsuit Actually Argues

The legal vehicle is an Article 78 petition — New York State's mechanism for challenging decisions by government agencies when a petitioner argues the agency acted arbitrarily, capriciously, or outside its legal authority. It is not a constitutional challenge to rent stabilization itself. The petition asks the court to annul the vote and send it back to the board for reconsideration, arguing the process was arbitrary and politically predetermined. The case lands squarely on one of Mayor Zohran Mamdani's signature campaign promises.

The landlords' core argument has three components. First, that Mayor Mamdani effectively guaranteed the outcome before the board deliberated — by campaigning on a rent freeze, appointing board members "predisposed to delivering a freeze," and mobilizing city resources including the Mayor's Office of Equity and Racial Justice and the Organize NYC initiative to fill public hearings with tenant advocates. Second, that the board majority ignored its statutory obligation to weigh owners' economic conditions when setting adjustments. The RGB's own Price Index of Operating Costs showed that expenses climbed 5.3% over the past year — and the landlords argue the board "ignored evidence of soaring landlord costs and manipulated the data to understate the impact of these costs." Third, that board member Christina Smyth's resignation and documented objections the morning of the vote constitute evidence that the deliberative process was compromised.

The seven plaintiff companies own or operate rent-stabilized buildings in Staten Island, Queens, the Bronx, and Brooklyn — deliberately chosen to represent small property owners from the outer boroughs rather than large institutional landlords. That framing is a deliberate legal and political choice: it makes the plaintiffs harder to dismiss as wealthy investors and emphasizes the human owners behind the regulated buildings.

Why This Case Is Different From Prior Failed Freeze Challenges

The RGB froze rents three times during Mayor de Blasio's tenure — in 2015, 2016, and 2020 — and each freeze was challenged. Each challenge failed. Understanding why landlords believe this case is different requires understanding what those prior cases argued and where they fell short.

The de Blasio-era lawsuits largely focused on whether the board was allowed to consider tenant affordability at all. Those efforts failed because courts ruled that tenant affordability was within the scope of factors the RGB was permitted to weigh. Attorney Deborah Riegel, co-counsel for the current plaintiffs, told Business Insider that this case is different — the legal argument isn't that tenant affordability can't be considered, but that the board considered affordability to the exclusion of its other statutory obligations, making the decision arbitrary rather than merely unpopular.

The distinction matters legally. A board that considers tenant affordability alongside owner costs and makes a judgment call is exercising discretion within its authority. A board that considers only one side of its statutory mandate while ignoring the other is potentially acting arbitrarily — which is exactly the standard courts can review under Article 78. The most damning evidence for this argument comes from board member Adán Soltren, who said during the April 9 RGB hearing that owners' cost considerations should be taken "with a grain of salt" and that he didn't want to dedicate even "an hour to it" — a statement that the plaintiffs are likely to lean on heavily in their brief as evidence that the board's consideration of owner costs was perfunctory rather than genuine.

Randy Mastro, the lead attorney for the landlords, summarized the argument directly: "Zohran Mamdani promised to deliver a rent freeze during his campaign, and then he went to extraordinary lengths as a new mayor to guarantee it." Whether that statement describes a political process operating as intended or a legal process that was compromised depends on how a court reads the distinction between mayoral influence over an independent regulatory body and mayoral direction of one.

What the Plaintiffs Are Asking For and the September Timeline

The petition requests three specific remedies: annulment of the June 25 vote; a remand to the board for reconsideration under a proper process; and an order maintaining Order #57 — the prior 3% and 4.5% increases — in effect until the board reaches a new decision. The third request is what makes the timing consequential. October 1 is the date the freeze takes effect. September is when the court has ordered the city to respond. That sequence means a decision on emergency relief — if the plaintiffs seek it — would need to come before October 1 to have any practical effect on the current lease cycle.

Courts are generally reluctant to issue emergency injunctions against regulatory decisions, particularly ones that affect a large and politically sensitive population. But the September hearing creates a window during which a judge could, in theory, order that Order #57 remain in effect pending full briefing and decision — which would mean stabilized leases commencing October 1 could be issued with 3% increases rather than 0%.

That scenario remains uncertain. The city will argue in September that the RGB acted within its authority, that the board properly considered all relevant factors, and that courts should defer to the board's expertise and discretion on the technical question of how to weigh competing economic data. Courts have consistently given the RGB significant deference on those questions in prior cases. Whether the specific evidence of procedural irregularity in this case — Smyth's resignation letter, Soltren's dismissal of owner cost data, the Organize NYC outreach — is sufficient to distinguish this case from precedent is a question only the court can answer.

What Each Outcome Means for Owners and Tenants

If the court dismisses the petition, the freeze takes effect October 1 as planned. Stabilized leases commencing on or after that date carry 0% increases. Building owners should plan their budgets accordingly and send renewals at 0%. Compliance with the freeze as issued is the only safe approach until a court orders otherwise.

If the court grants emergency relief maintaining Order #57 in effect pending a full decision, stabilized leases commencing October 1 could potentially be issued with 3% one-year or 4.5% two-year increases — but only if a court explicitly orders it before that date. Owners should not issue renewals with any increase above 0% on the assumption that the lawsuit will succeed. The appropriate course is to wait for an explicit court order before deviating from the freeze.

If the court ultimately annuls the RGB vote and remands to the board, the board would need to reconvene and conduct a new proceeding. That process could take months, during which the status of leases already issued under the freeze would be legally complex — a scenario with no clean precedent. Tenant organizations would almost certainly seek to intervene to protect the freeze, and the resulting litigation could extend well into 2027.

The most likely near-term outcome, based on the precedent from prior freeze challenges, is that the court allows the freeze to take effect while it considers the full merits of the case. That is not a certainty — this case has distinguishing features that prior cases did not — but it is the base case that building owners should be planning around. At Dover Property Group, we will update our clients as the September hearing and any subsequent court orders develop. If you have questions about your renewal obligations in the meantime, our team is glad to walk through the current compliance picture with you.

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Sources: The Real Deal — Landlords Sue RGB Over Mamdani's Rent Freeze, July 22, 2026 · The Real Deal — Rent Freeze Lawsuit Tests Limits of City Hall Influence Over RGB · Commercial Observer — NYC Landlords Sue Rent Guidelines Board Over Rent Freeze · amNewYork — Landlords Sue to Overturn Mamdani's NYC Rent Freeze · Yahoo Finance / Business Insider — Landlords Are Suing Over the NYC Rent Freeze · City Journal — Mamdani's Rent Freeze Goes to Court · Brownstoner — Landlords File Suit to Stop Mamdani's Rent Freeze · Patch — Landlords Sue NYC Over Rent Freeze

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About the Author
Dover Property Group is a New York City property management firm working with building owners and tenants across all five boroughs. Our team tracks market conditions, compliance requirements, and neighborhood-level trends to help owners protect their assets and tenants navigate one of the most complex rental markets in the country.