Mayor Zohran Mamdani has extended by one month the deadline for New York City homeowners to apply for an exemption from his new pied-à-terre tax, which took effect July 1. Homeowners across the five boroughs who believe they qualify now have until Sept. 18 to file, according to City Hall; the previous deadline was Aug. 21.

What the Left Is Saying

City officials defend the tax as targeting high-value second homes, but they say the extended deadline ensures no one is unfairly penalized while documentation is gathered. The Department of Finance explained it needed more time for homeowners to prove primary residence and has since clarified that only those who received mailed notices are required to take further action.

What the Right Is Saying

Real-estate and business leaders warned the tax could drive investment out of the city, while Griffin described Mamdani's announcement video as "creepy and weird" during a discussion at the Milken Institute Global Conference on May 6, saying he watched it three times.

What the Numbers Show

The pied-à-terre tax imposes an annual surcharge on certain high-value New York City homes worth more than $5 million that are not the owner's primary residence. It applies during the 2026-27 and 2027-28 property-tax years to secondary residences — including one-, two- and three-family properties — while individual condo and co-op units valued at $1 million or more are also subject to it.

On July 24, the city published a supplemental market value roll listing more than 900,000 properties without explaining that most would not be taxed; DOF has since clarified it mailed surcharge notices to only 17,000 homeowners and updated its webpage to state that only those who received notification by mail are required to take further action. The extended deadline applies to anyone who received notices from DOF containing the phrase "You may be subject to..."

The Bottom Line

The one-month extension gives affected homeowners breathing room to document their primary residence before the Sept. 18 cutoff, while city officials work to correct earlier confusion over which of the hundreds of thousands of listed properties are actually subject to the surcharge.