District of Columbia Code Division VII. Property. § 42-1102.02. Transfer of economic interest defined.

(a) A transfer of an economic interest in real property occurs upon the conveyance, vesting, granting, bargaining, sale, or assignment, directly or indirectly, of a controlling interest by 1 or more persons or by 1 or more transactions, within any 12-month period, in any corporation, partnership, association, trust, or other entity that, during the 12-month period immediately preceding the transfer of an economic interest in real property:

(b) For the purposes of subsection (a) of this section, a transfer of a controlling interest includes the aggregate of the transfer of any legal, equitable, beneficial, or other ownership interest in:

(c) Notwithstanding any other provision of this section, as of October 1, 2009, every transfer of an interest in a cooperative housing association in connection with the grant, transfer, or assignment of a proprietary leasehold or other proprietary interest, in whole or in part, shall be a transfer of an economic interest.