The Pied-à-Terre Tax Says $5 Million. For Upper East Side Co-ops, the Number That Matters Is Different.

"As a practical matter, the PAT Tax requires a co-op board to collect money from shareholders to satisfy someone else's tax liability." That line comes from a lawsuit filed in late September by the corporation that owns the Montclair, a co-op at East 75th Street and Madison Avenue, along with several of its owners. The Real Deal reported that the case is financially backed by the Real Estate Board of New York.

Most coverage of New York City's new non-primary residence surcharge has focused on the people who owe it. The Montclair complaint centers on how the surcharge reaches the building. In a co-op, the surcharge is billed to the building, and the date that decides who owes it has already passed. That shifts how co-op deals get reviewed, negotiated and closed this fall, and it applies even when the buyer plans to live in the apartment full time.

The $5 million headline describes houses

When Governor Hochul signed the budget in May, the state described the surcharge as applying to "high-value – $5 million or more – second homes." That figure is accurate for one-, two- and three-family homes. For condos and co-ops, the Department of Finance uses a different line. For tax years 2026-27 and 2027-28, units "valued by DOF at $1 million or more" may be covered.

DOF's explanation is that state law values co-ops and condos differently from other residential property. In the city's words, a co-op or condo valued by DOF at $1 million or more "is comparable to a single-family home valued at $5 million or more." So the $1 million is a DOF valuation, not a sale price. For a co-op apartment, the state statute imputes the unit's value by multiplying DOF's market value for the whole co-op property by that apartment's share of the building.

DOF lists these rates for the first two years:

For an apartment, the share count in the building's records matters more than the asking price on the listing sheet.

Where the bill actually lands

In a condo, the surcharge goes on the individual owner's tax bill. In a co-op, the statute adds every qualifying unit's surcharge to the cooperative corporation's property account, and the corporation then collects from the shareholder. Brick Underground noted that co-op property taxes already flow through monthly maintenance, so boards now have to work out how to recover the surcharge from the shareholders it applies to.

REBNY spelled out the stakes in its testimony to the City Council. If one shareholder doesn't pay, interest accrues at 18% a year against the co-op's entire property tax account. If the lien grows large enough, it can be sold, and many co-op mortgages contain default provisions triggered by unpaid tax liens. REBNY also pointed out that many proprietary leases predate the surcharge and may not let a board bill it as additional rent, charge late fees or treat nonpayment as a default.

Boards have a fix in principle, but in practice it isn't simple. The Real Deal reported that attorneys are advising boards to look at amending proprietary leases. One attorney said most co-ops may not do it, either because amending is difficult or because boards don't know they should. Brick Underground quoted attorney Parag Parekh saying his firm treats the charge as "additional rent," which is one firm's legal position, not a citywide standard.

January 5 already happened

For the first year, primary residence is tested as of the January 5, 2026 taxable status date. The law took effect May 28, 2026, almost five months later. Anything that changed hands in between falls into a gap.

REBNY's testimony describes the problem directly. A seller who wasn't a primary resident on January 5 and closed before the law existed "received full sale proceeds and departed." Meanwhile, the apartment can carry building-level lien exposure tied to that seller's status, even if the new owner lives there full time. DOF's answer, as stated in its final rules, is that parties may structure their transaction documents to allocate the risk. REBNY says that does nothing for closings that already happened and leaves co-ops with no practical way to collect from former shareholders.

That is the central claim in the Montclair suit. According to The Real Deal, boards would have to track down shareholders who sold and moved out between January 5 and May 28. Because the tax applies retroactively, the suit argues, boards never had a chance to amend their leases before those owners left.

The Upper East Side has a deep stock of prewar co-ops, including Park Avenue and Madison Avenue buildings with long-tenured shareholders and owners whose main home is elsewhere. That combination is why the gap shows up here.

What a co-op deal looks like this fall

All of this changes the document review for a co-op purchase or sale, whatever the price. Based on the reporting and guidance above, a buyer's attorney, a seller's attorney or the managing agent may need to answer these questions this season:

1. Did this unit receive a surcharge notice? DOF sent letters to more than 17,000 owners, out of more than 900,000 properties listed on a supplemental roll. DOF says being on the roll alone "does not mean that it is subject to the surcharge."
2. Was an exemption filed and approved? Exemptions cover units that are the primary residence of the owner, a tenant, an immediate family member, a majority owner of an entity, or a trust's sole beneficiary. Under the law's definitions, a tenant's lease has to be bona fide, arm's length and at least one year long.
3. Who owned the shares on January 5, 2026? For units that changed hands after that date, the contract is where DOF has pointed buyers and sellers to allocate the risk.
4. What does the proprietary lease let the board do? This determines whether the board can bill a surcharge as additional rent or treat nonpayment as a default.
5. How will the board view a buyer who won't live there full time? The Real Deal reported attorneys saying the collection burden is making some co-ops wary of selling to buyers who won't use the apartment as a primary residence. In Brick Underground's third-quarter market roundup, one Manhattan agent said the tax is "fueling a shift toward condos."

This is general information, not legal, tax or financial advice. Your own exposure depends on your building, your documents and your ownership structure, so confirm it with your real estate attorney and accountant.

The top of the market is already moving more carefully. In an October 6 roundup, CityRealty reported brokers saying hesitation had begun among second-home buyers. The same report said Residence #9 at The Giorgio Armani Residences, 760 Madison Avenue, closed for $23 million, just over 30% below the price the seller asked when it was listed in April 2025. Pricing hasn't broken more broadly. CityRealty puts the Upper East Side's average condo price per square foot up 1.7% year over year so far in 2026.

The dates still ahead

The exemption window closed on October 13, 2026, after several extensions. Crain's New York Business reported on October 14 that the city had told more than 6,800 owners they don't owe the surcharge this year, leaving fewer than 10,000 still on the hook. Here is what comes next:

• Before November 6, 2026: Oral argument in the city's appeal of the ruling that ordered it to redo the rollout. An appellate stay lets the city keep implementing the surcharge in the meantime.
• By November 10, 2026: The appellate panel's deadline for a decision, as reported by Habitat.
• January 1, 2027: Surcharge amounts appear on the property tax bill due that day.
• March 1, 2027: The NYC Tax Commission deadline for Class Two challenges to DOF's valuation or residency determination. Class One properties have until March 15.

Two other suits, filed in Suffolk County, challenge the tax itself on constitutional grounds. One is the Montclair case, and the other was brought by a group of out-of-state owners.

A few questions worth asking directly

I'm buying a co-op to live in full time. Does any of this affect me? It can. In a co-op, the surcharge sits on the building's tax account, so a prior shareholder's January 5 status or a neighbor's nonpayment is a building-level issue, as REBNY has described. That makes it part of the building's financial picture during due diligence.

Is the $1 million figure what I'd pay for the apartment? No. It is DOF's valuation of the unit, which for a co-op is figured from the building's DOF value and the apartment's shares. DOF describes that $1 million level as generally comparable to a $5 million single-family home.

Can a valuation still be challenged after October 13? DOF says owners who disagree with its valuation can go to the NYC Tax Commission. The Tax Commission will consider primary residency only when it's paired with a valuation challenge, and once you file there, DOF defers to the commission's decision.

I'm thinking about selling my Upper East Side co-op. What should I prepare? Have the January 5 status of your unit documented, along with any DOF notice or exemption determination, before a buyer's attorney asks for them. The Upper East Side seller's guide covers the rest of the prep timeline, and our Upper East Side neighborhood page covers the blocks themselves.

If you're weighing a co-op or condo on the Upper East Side this season and want help sorting out which documents to request and which questions to raise early, Josie Hubschman can work through it with you and your attorney before the board package goes in. Let's Connect.