Timeline: from a 2014 proposal to a 2031 sunset

Updated 2026-08-02.

The whole chronology in one place, in order, with the source for each entry.

The surcharge that owners are answering notices about in 2026 is twelve years older than the notices. The idea, the first bill, the collapse of that bill, and the version that finally passed are four different things, and only the last of them is law.

Before the law: 2014 to 2019

DateWhat happened?
September 22, 2014The Fiscal Policy Institute proposes a surcharge on the most expensive New York City pied-à-terre residential units.
January to April 2019The Griffin penthouse sale revives the Hoylman bill. It collapses over cooperative valuation problems and is replaced by an expansion of the mansion tax.

2026: proposal, enactment, rollout

DateWhat happened?
April 15, 2026Governor Hochul and Mayor Mamdani announce the proposal, aimed at second homes valued at $5 million or more, projected at about $500 million a year.
April 30, 2026The Comptroller's office scores it at $340 million to $381 million, analyzing 19,107 properties and 11,226 after a market-value adjustment.
May 28, 2026Enacted in the state budget as Part HH of Chapter 59 of the Laws of 2026, adding Tax Law Article 30-C and Administrative Code Title 11, Chapter 32.
June 5, 2026The Department of Finance proposes its rules, 19 RCNY Chapter 62.
July 1, 2026The surcharge takes effect.
July 9, 2026Public hearing on the proposed rules. Thirty-five written comments are submitted.
July 14, 2026The final rule is adopted, effective immediately.
July 22, 2026Notices are mailed, each with a unique security code and a respond-by date.
July 24, 2026The supplemental market value roll, the assessment roll addendum, is published, listing properties that may be subject, with Phase One values. The Department of Finance's own pages date the publication July 24; early firm coverage framed it around July 25.
July 26 and 27, 2026The published roll is scraped into name-and-address lists, and a privacy argument follows.
August 1, 2026Mayor Mamdani and Commissioner Lee announce a four-week extension of the exemption application deadline, to September 18, 2026, for everyone who received a notice.

Still on the calendar

DateWhat it is?
August 30, 2026Department of Finance statutory outside date to transmit year-one determinations. Not an owner deadline, and the extension announcement did not address it.
September 18, 2026Response deadline, one date for homes, condominiums, and cooperative units. Extended August 1, 2026 from the printed August 21 and August 24.
November 2026Bills issued.
December 31, 2026Final assessment roll addendum due.
January 1, 2027First payment due, with the second semi-annual property tax installment.
March 1 and March 15, 2027Tax Commission Form TC107 deadlines, Class 2 and Class 1.
July 1, 2028Phase Two: condominiums and cooperatives move to comparable-sales valuation under a single $5 million threshold.
June 30, 2031The surcharge sunsets.

Sources