On 24 July 2026 the New York City Department of Finance published a supplemental market value roll tied to the new non-primary-residence surcharge, sometimes called the pied-à-terre tax. It arrived as two zipped CSV files on a nyc.gov download path. This site is those files, made searchable and mapped.
Appearing on this roll does not mean a property owes anything. DOF states the roll “includes, but is not limited to” properties that may be subject to the surcharge. Of 959,710 rows, 30,416 are individual residences in a surcharge band — 3.17% — and most of those are exempt.
Every surcharge number on this site is one multiplication: DOF’s published market value for the property, times DOF’s published rate for its band. Nothing is modelled or estimated. The rates, for tax years 2026-27 and 2027-28:
| Type | DOF market value | Rate |
|---|---|---|
| 1–3 family home | $5,000,000 – $15,000,000 | 0.80% |
| $15,000,000 – $25,000,000 | 1.05% | |
| $25,000,000 and above | 1.30% | |
| Condo or co-op unit | $1,000,000 – $3,000,000 | 4.00% |
| $3,000,000 – $5,000,000 | 5.25% | |
| $5,000,000 and above | 6.50% |
The surcharge does not apply where the property is the primary residence of the owner, a tenant or subtenant, an immediate family member, one or more people holding a majority interest in the owning entity, or the sole beneficiary of a trust.
The roll has no coordinates, only addresses and parcel identifiers. Points come from four tiers, and every property records which one it used — visible on its page.
Where a public source connects an owner to other public records — property transfers, campaign contributions, securities filings — the site shows it with a link to the underlying record and a match confidence. The database cannot store a claim without a source URL.
Two things are deliberately absent. There are no scraped social-media photographs of private individuals; portraits come only from freely licensed sources and official government images. And there are no estimated net-worth figures, because no such dataset exists for these owners — any number would be invented. What is shown instead is the combined value of the properties actually on this roll, which is a fact.
Built by Magneton Labs. The code is open source, and the pipeline that produced everything here runs from the same repository: github.com/MagnetonIO/nyctax.
It is built to take more than one dataset. Adding another government source means implementing five functions and a display config against a documented interface — the contributing guide in the repository walks through it, and suggests a few worth doing next.
If a record here is wrong, it is either wrong in DOF’s file or wrong in how this site processed it, and both are worth fixing. The source files are linked below so you can check. To challenge a valuation or claim an exemption, that goes to DOF and the Tax Commission, not to us.