Raising rent in New York State

[Kaitlyn Recny]

My husband and I just bought our first triplex in upstate NY. WE are inheriting two tenants, and one unit will be vacant. The two who have lived in the other two units have been there for an extreme period of time; one for 40 years and one for 10 years. However, they are paying WELL below market value for our area ($525 when market rate for our area is $750-$900 for similar apartments). The units are dated, but still in good shape. We plan to renovate the vacant unit and raise the rent. However, we also plan to raise the rents for the two remaining tenants. It is my understanding that, in NY, if the tenant has lived in the unit longer than 20 years a 90 day notice is required prior to raising the rent above 5%. My question is, does this also apply if they are on a “month to month” lease? We actually aren’t even sure if there is a written lease in place for these tenants anymore (we are closing on the property next week so don’t have all of the details yet). Any input would be appreciated. Thanks!