Three homeowners sued Mayor Zohran Mamdani and the city finance commissioner, challenging a supplemental tax roll that listed more than 900,000 properties and notices sent to some residents. The complaint does not seek to strike down the underlying surcharge.
The annual surcharge applies only to qualifying non-primary residences. For 2026–27 and 2027–28, one- to three-family homes enter at a city market value of $5 million, with rates from 0.8% to 1.3%; condos and co-ops enter at $1 million, with rates from 4% to 6.5% under the city’s separate valuation rules. Primary residences used by an owner, tenant or immediate family member are exempt.
The Department of Finance says only about 17,000 owners received “may be subject” letters and that appearing on the much larger public roll does not mean a bill is due. The lawsuit argues that the rollout wrongly put the burden on residents to prove exemptions and unnecessarily exposed names and addresses. The city extended the exemption deadline to Sept. 18; any surcharge due appears on the Jan. 1, 2027 property-tax bill.