Regarding the security deposit portion of your question; for a market-rate apartment, a landlord can ask for as large of a security deposit as he or she likes. A large security deposit is often used to help qualify an otherwise unqualified applicant. If the prospective tenant doesnâ€™t meet the income requirement (typically annual income needs to meet or exceed 40x the monthly rent), has poor credit, or may have some other indicator of risk to the landlord, the prospective tenant may be able to provide a larger security deposit to offset the perceived risk of their tenancy. Unlike market-rate apartments, security deposits for rent-stabilized apartments are regulated. The landlord may not ask for more than one monthâ€™s rent as security. To determine if an apartment you're considering is rent stabilized, check the lease, as rent stabilized apartments are required to use a specific lease indicating the rent stabilization.