A unit owners' association must be organized no later than the date the first unit in the common interest community is conveyed. The membership of the association at all times consists exclusively of all unit owners or, following termination of the common interest community, of all former unit owners entitled to distributions of proceeds under section 2-118 or their heirs, successors, or assigns. The association must be organized as a profit or nonprofit corporation, trust, partnership, or as an unincorporated association.