N.Y. Emergency Tenant Protection Act § 10-a
Units subject to this law may be sublet pursuant to section two hundred twenty-six-b of the real property law provided that (a) the rental charged to the subtenant does not exceed the legal regulated rent plus a ten percent surcharge payable to the tenant if the unit sublet was furnished with the tenant's furniture; (b) the tenant can establish that at all times he has maintained the unit as his primary residence and intends to occupy it as such at the expiration of the sublease; (c) an owner may terminate the tenancy of a tenant who sublets or assigns contrary to the terms of this section but no action or proceeding based on the non-primary residence of a tenant may be commenced prior to the expiration date of his lease; (d) where an apartment is sublet the prime tenant shall retain the right to a renewal lease and the rights and status of a tenant in occupancy as they relate to conversion to condominium or cooperative ownership; (e) where a tenant violates the provisions of subdivision (a) of this section the subtenant shall be entitled to damages of three times the overcharge and may also be awarded attorneys fees and interest from the date of the overcharge at the rate of interest payable on a judgment pursuant to section five thousand four of the civil practice law and rules; (f) the tenant may not sublet the unit for more than a total of two years, including the term of the proposed sublease, out of the four-year period preceding the termination date of the proposed sublease. The provisions of this subdivision (f) shall only apply to subleases commencing on and after July first, nineteen hundred eighty-three; (g) for the purposes of this section only, the term of the proposed sublease may extend beyond the term of the tenant's lease. In such event, such sublease shall be subject to the tenant's right to a renewal lease. The subtenant shall have no right to a renewal lease. It shall be unreasonable for an owner to refuse to consent to a sublease solely because such sublease extends beyond the tenant's lease; and (h) notwithstanding the provisions of section two hundred twenty-six-b of the real property law, a not-for-profit hospital shall have the right to sublet any housing accommodation leased by it to its affiliated personnel without requiring the landlord's consent to any such sublease and without being bound by the provisions of subdivisions (b), (c) and (f) of this section. Commencing with the effective date of this subdivision, whenever a not-for-profit hospital executes a renewal lease for a housing accommodation, the legal regulated rent shall be increased by a sum equal to fifteen percent of the previous lease rental for such housing accommodation, hereinafter referred to as a vacancy surcharge, unless the landlord shall have received within the seven year period prior to the commencement date of such renewal lease any vacancy increases or vacancy surcharges allocable to the said housing accommodation. In the event the landlord shall have received any such vacancy increases or vacancy surcharges during such seven year period, the vacancy surcharge shall be reduced by the amount received by any such vacancy increase or vacancy surcharges.
N.Y. Emergency Tenant Protection Act Law § 10-a