New York Consolidated Laws, Estates, Powers and Trusts Law - EPT § 6-2.2 When estate is in common, in joint tenancy or by the entirety

(a) A disposition of property to two or more persons creates in them a tenancy in common, unless expressly declared to be a joint tenancy.

(b) A disposition of real property to a husband and wife creates in them a tenancy by the entirety, unless expressly declared to be a joint tenancy or a tenancy in common.

(c) A disposition on or after January first, nineteen hundred ninety-six of the shares of stock of a cooperative apartment corporation allocated to an apartment or unit together with the appurtenant proprietary lease to a husband and wife creates in them a tenancy by the entirety, unless expressly declared to be a joint tenancy or a tenancy in the common.

(d) A disposition of real property, or a disposition on or after January first, nineteen hundred ninety-six of the shares of stock of a cooperative apartment corporation allocated to an apartment or unit together with the appurtenant proprietary lease, to persons who are not legally married to one another but who are described in the disposition as husband and wife, spouses, husbands, or wives creates in them a joint tenancy, unless expressly declared to be a tenancy in common.

(e) A disposition of property to two or more persons as executors, trustees or guardians creates in them a joint tenancy.

(f) Property passing in intestacy to two or more persons is taken by them as tenants in common.