The NYC 15-year tax abatement is the baseline benefit under Real Property Tax Law Section 421-a. It exempts a newly constructed residential building from the property tax increase caused by that construction for 15 years: 11 years at the full exemption, followed by a four-year phase-out.1Housing Preservation & Development. 421-a The 421-a program is closed to new construction starts, so the benefit now matters mainly to owners of buildings that already have it, buyers considering a unit in one of those buildings, and developers finishing projects that began within the program’s deadlines.
What the Exemption Actually Covers
The abatement does not wipe out your property tax bill. It only shields the increase in assessed value that resulted from the new construction. The land value and any pre-existing assessment stay taxable.2New York State Senate. New York Real Property Tax Law 421-A – Affordable New York Housing Program
So picture a vacant lot assessed at $200,000. After construction, the building is assessed at $2 million. The exemption covers the $1.8 million difference. You still pay taxes on the underlying $200,000 every year the abatement is in effect.
For the first 11 years, 100 percent of the construction-related increase is exempt. Starting in year 12, a 2.2 percent surcharge is added each year, reaching a cumulative 8.8 percent by year 15.3Homes and Community Renewal. Surcharges and Fees At the end of year 15, the exemption ends. The full assessed value becomes taxable.
Who Qualifies for the 15-Year Track
The 15-year benefit is the baseline tier under RPTL 421-a. It generally applies to new multi-family buildings (hotels excluded) constructed outside the city’s Geographic Exclusion Area.2New York State Senate. New York Real Property Tax Law 421-A – Affordable New York Housing Program Buildings inside the GEA can also receive benefits, but only if at least 20 percent of units are set aside as affordable for low- and moderate-income households, with those affordable rentals rent-stabilized for 35 years.1Housing Preservation & Development. 421-a Projects with affordable units that meet further requirements may qualify for 20- or 25-year benefit periods instead.
The Geographic Exclusion Area
The GEA covers all of Manhattan plus designated sections of Brooklyn, Queens, the Bronx, and Staten Island. HPD publishes borough-by-borough maps on its 421-a page.1Housing Preservation & Development. 421-a Outside the GEA, the 15-year track is available without any affordability component. Inside the GEA, the 20 percent set-aside applies.
Closed Construction Windows
No new project can begin construction today and receive 421-a benefits. The program operated in two phases, and both are now closed to new starts:
- The original 421-a(1-15): projects had to commence construction on or before December 31, 2015.
- 421-a(16), the “Affordable Housing New York” version: projects had to commence construction between January 1, 2016 and June 15, 2022, and must be completed by June 15, 2026. A deadline extension to June 15, 2031 was granted to projects that submitted a Letter of Intent by September 12, 2024 and selected certain affordability options.
Developers who started within these windows can still claim the benefit once they complete construction and apply.1Housing Preservation & Development. 421-a
Floor Area and Conversion Limits
Buildings that incorporate a pre-existing structure through conversion or alteration can qualify, but no more than 49 percent of the total floor area can consist of the converted portion.2New York State Senate. New York Real Property Tax Law 421-A – Affordable New York Housing Program Floor area is measured from the exterior faces of exterior walls and includes all floors of the dwelling plus any accessory structures on the lot. Most developers have an architect or expediter certify the calculation before filing, because getting it wrong is one of the faster ways to lose eligibility.
How to Apply
If a project is still in the pipeline and eligible, the application runs through two agencies in sequence.
You file first with HPD. The package needs the property’s tax block and lot numbers, proof of construction commencement and completion dates, a Certificate of Occupancy from the Department of Buildings, and documentation of compliance with any applicable affordability requirements. GEA projects also need a regulatory agreement and a unit-by-unit breakdown of rents and income targeting. Independent cost certifications may be required to verify total project expenditure. The filing fee is $100, paid by wire transfer or ACH only.1Housing Preservation & Development. 421-a HPD accepts the application by email with a mailed paper original to its Tax Incentive Programs office at 100 Gold Street; the email date is your official filing date.4NYC Housing Preservation & Development. Tax Incentives – HPD
If HPD approves, it issues a Certificate of Eligibility.5NYC Department of Finance. 421a Exemption If HPD asks for additional documents, respond by the deadline it sets. Letting a request lapse can kill the application.
With the certificate in hand, you then file DOF’s own 421-a application. DOF applies the exemption to the property’s account, and the reduction appears on the quarterly tax bill. Expect several months from initial HPD filing to the first reduced bill.5NYC Department of Finance. 421a Exemption
Compliance While the Benefit Runs
Receiving the abatement does not end the paperwork. Two annual filings matter most.
DHCR Rent Registration
Affordable units in a 421-a building must remain rent-stabilized for the term set in the regulatory agreement. Owners of rent-stabilized buildings have to file annual registration statements with the Division of Housing and Community Renewal by July 31 each year, reflecting unit information as of April 1.6Homes and Community Renewal. Rent Registration Filings go through DHCR’s Owner Rent Regulation Application system. Late registrations carry a penalty of $500 per unregistered unit for each month they remain late, which adds up quickly in a large building.
Charging rent above the legal stabilized amount is a separate violation. A willful overcharge can bring treble damages, meaning three times the excess rent collected, plus an order reducing the legal rent going forward.7Homes and Community Renewal. Rent Increases and Rent Overcharge
RPIE Filings With DOF
Owners of income-producing properties with an actual assessed value above $40,000 must file a Real Property Income and Expense statement with DOF each year. The RPIE-2025 deadline is June 1, 2026. Properties assessed at $750,000 or more must also file a rent roll addendum. Non-filing penalties scale with assessed value, from $300 for smaller properties up to $100,000 for those assessed at $25 million or more, and three consecutive years of non-filing can trigger an additional penalty of five percent of the final assessed value.8NYC Department of Finance. Real Property Income and Expense (RPIE) Statements
What Happens When the 15 Years Run Out
This is where many owners and almost all buyers get caught off guard. When the benefit expires, the full assessed value becomes taxable. Because city property tax rates are high and the exemption often shields millions of dollars in assessed value, the jump can be sharp. Monthly maintenance in a co-op or common charges in a condo can rise by hundreds of dollars per unit effectively overnight.
The four-year phase-out softens the transition, but the annual 2.2 percent increments are small relative to the gap that remains in year 16. If you are considering a unit in a building with an active 421-a abatement, the single most important question is how many years of benefit remain. A unit that looks affordable because of low current taxes may become much more expensive to carry once the benefit burns off. Sellers are not required to volunteer this, so check the property’s benefit status on the Department of Finance website or request a benefits summary from the managing agent before you commit.
Related Programs That Are Not 421-a
Two other programs come up often enough that it helps to know they are different. RPTL Section 485-x, the Affordable Neighborhoods for New Yorkers program, is the successor for projects that begin construction after June 15, 2022, with different benefit periods, affordability rules, and construction-wage requirements than 421-a.9NYC Housing Preservation & Development. 485-x: Affordable Neighborhoods for New Yorkers J-51, meanwhile, is a rehabilitation incentive for existing residential buildings rather than new construction, with its own tiers and its own application process.10NYC Housing Preservation & Development. Tax Incentives J-51 Neither extends or replaces an existing 15-year 421-a benefit on a building that already has one.