State lawmakers failed to reach an agreement on extending rent regulations before the midnight deadline, but the impact on tenants is expected to be minimal.
Unless a lease expired today, tenants are still protected by their existing lease.
Landlords cannot raise rents or evict them without advance notice.
Legislators also intend to make any rent deal retroactive.
Both Mayor Bill de Blasio and Governor Andrew Cuomo have said they will go after anyone who tries to exploit the lapse of the law.
Governor Cuomo is vowing to keep the legislature in Albany until a deal is passed.
Mayor de Blasio says there's been an increase in calls to the city's 311 information hotline from tenants asking about the expiration.
If you have a problem with a landlord, the city's Public Advocate has set up a hotline at 212-669-7250.