Before June 2019, a rent-stabilized apartment could legally become deregulated in two ways: the legal rent crossed a set dollar threshold when the unit went vacant, or the tenant's income and rent both crossed separate thresholds for two years running. New York's Housing Stability and Tenant Protection Act (HSTPA) closed both paths that June, so an apartment that was stabilized after that date almost never has a legal route out of stabilization. If your landlord tells you a post-2019 apartment "became" market rate, that claim deserves a hard look, not automatic trust.
Before you take a landlord's word for a unit's status, search the address on Building Health X to pull violations, complaints and registration history the listing will not mention.
How an Apartment Lost Rent Stabilization Before 2019
Two mechanisms did almost all of the deregulating before the law changed, and understanding them is the fastest way to spot a claim that does not hold up.
High-Rent Vacancy Deregulation
Under the old rules, once a stabilized unit's legal rent crossed a set dollar figure and the tenant then moved out, the landlord could take the apartment out of stabilization entirely. The threshold climbed over time and reached $2,733.75 a month by the time the rule was repealed. A landlord who could push the legal rent over that line, often through a large vacancy increase plus renovation costs billed to the unit, could turn a stabilized apartment into a market-rate one the moment it emptied out.
High-Income Deregulation
The second path applied to occupied units. If the tenants' combined household income exceeded a set amount for two consecutive years, and the legal rent was also above a separate threshold, the landlord could apply to deregulate the apartment while the same tenant was still living there. This route required both conditions to hold for two straight years, and DHCR had to approve the application.
Why HSTPA Closed Both Paths in 2019
Governor Cuomo signed the Housing Stability and Tenant Protection Act on June 14, 2019, and it repealed high-rent vacancy deregulation and high-income deregulation outright. Neither path has been legally available since. Tenant advocates estimate the change saved roughly 15,670 apartments that were already on track to lose stabilization under the old rules. For any apartment that was stabilized on or after that date, there is no ordinary vacancy or income event that can legally take it out of the system. A landlord claiming otherwise for a recent vacancy is describing something the law no longer allows.
421-a and J-51 Tax Benefit Riders
A separate category of buildings gets stabilization through a tax break rather than the building's age or unit count. Owners who take 421-a or J-51 tax benefits have to keep every unit rent stabilized for as long as they hold the benefit, and they have to tell tenants about it. The lease has to spell out the exact date the tax benefit expires, printed in at least 14-point type, and that disclosure has to appear in the first lease and in every renewal after it. If an owner skips that notice, the consequence is not a slap on the wrist: the landlord can lose the ability to ever lawfully remove the unit from stabilization, even after the tax benefit itself runs out.
If your building has a 421-a or J-51 tax exemption and your lease never mentioned it, that gap alone is worth raising, since it can mean your unit stayed stabilized on paper even if the landlord has been billing you a market rent.
Warning Signs of an Illegal Deregulation
- A stabilized tenant moved out after 2019, and the unit came back on the market as "no fee, market rate." Since no legal deregulation path exists for that timeline, this pattern is one of the clearest signs of a problem.
- The landlord stopped filing annual rent registrations with DHCR. A gap in the registration history does not deregulate the unit. It can just mean the owner quietly stopped reporting.
- The building has 421-a or J-51 benefits but your lease never disclosed them. Missing riders are a documented pattern in enforcement cases, not a rare clerical slip.
- A sudden, steep jump between the last registered legal rent and what you are being asked to pay, with no renovation paperwork or capital improvement filing to explain it.
None of these facts alone proves fraud, but any of them is a reason to pull your building's rent history before you sign or renew. The pattern that shows up most often in enforcement cases is not a single missing document. It is several of these signs stacking together: a registration history that stops cold in a given year, a lease that never mentions a tax benefit the building is clearly receiving, and asking rents that jumped well past anything the last legal rent on file would support.
What Illegal Deregulation Looks Like in Practice
On December 1, 2025, New York Attorney General Letitia James and HCR Commissioner RuthAnne Visnauskas sued a New York City real estate developer, alleging it illegally deregulated at least 159 rent-stabilized apartments across 31 buildings in Brooklyn and Queens, while telling tenants, lenders and state regulators the units were market rate. The Attorney General's office is seeking reregulation of the units, treble damages on the overcharges, and an independent audit of the company's full portfolio. It is a live example of the exact pattern renters ask about: a landlord asserting market-rate status on units that, by law, should have stayed stabilized.
How to Check Your Rent History and Push Back
You can request your apartment's rent history from DHCR at no charge, and it will show the registration record, including any gaps or sudden jumps. Requesting it does not require a lawyer, just proof you live there. The record lists every legal rent DHCR has on file back to the base date, so a gap where nothing was filed for several years, or a jump that lines up with a change of ownership, tells you where to focus your questions.
If the history shows an overcharge, you can file a complaint with DHCR's Office of Rent Administration. For overcharges collected since June 14, 2019, the law lets you look back six years, and treble damages are mandatory, not optional, once DHCR or a court finds the overcharge was willful. Where the landlord's conduct looks like an outright scheme to hide a unit's stabilized status, DHCR or a court can also look at rent records older than that six-year window to work out what the legal rent should have been, under the fraud exception the state's Court of Appeals recognized in its 2020 Regina Metropolitan ruling.
Start by confirming whether your apartment is rent stabilized in the first place, then request the rent history to see the paper trail behind your landlord's claim. If the numbers do not add up, an overcharge complaint is the next move, regardless of whether the original deregulation itself turns out to have been legal.
The Community Service Society's analysis of the 2019 rent law reforms is a useful plain-language rundown of what changed and why regulators consider aggressive deregulation claims a compliance target rather than a paperwork formality.
Frequently Asked Questions
How Can a Rent Stabilized Apartment Become Deregulated Now?
For units stabilized on or after June 14, 2019, there is no ordinary legal path to deregulation. The two routes that used to exist, high-rent vacancy and high-income deregulation, were both repealed that year. A unit can still leave stabilization in narrow cases, such as a 421-a or J-51 benefit expiring after the owner properly disclosed it and followed the required phase-out steps.
What Should I Do if I Think My Apartment Was Illegally Deregulated?
Request your rent history from DHCR first. If it shows a stabilized unit that later disappears from the registration record without an explanation like a lawful high-rent vacancy before 2019, file an overcharge complaint with DHCR's Office of Rent Administration and keep copies of every lease you can find.
Does My Landlord Have to Tell Me if the Building Gets 421-a or J-51 Benefits?
Yes. The lease has to state the tax benefit and its exact expiration date in at least 14-point type, in the first lease and every renewal. If that disclosure never happened, the landlord may not be able to lawfully take your unit out of stabilization at all.
How Far Back Can I Go if I Find an Overcharge?
For overcharges collected since June 14, 2019, you can generally look back six years, and treble damages are mandatory if the overcharge was willful. If there is evidence of fraud in how the unit was deregulated, DHCR or a court can examine older records to establish the correct legal rent.
Is It Illegal for a Landlord to Lie About Whether a Unit Is Stabilized?
Yes. Misrepresenting a unit's regulatory status to a tenant, a lender or the state is the core allegation in active enforcement cases, including a December 2025 Attorney General lawsuit over 159 apartments in Brooklyn and Queens. Tenants harmed by the misrepresentation can recover overcharges, and in fraud cases, treble damages.
Need help with your apartment?
Tell us what you need and get free quotes from local NYC pros.