New York Laws
Part 2 - Estates Classified as to Number of Persons
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.

Structure New York Laws