Iowa Code § 498.13: Automatic cancellation — revocation.

It shall become void upon the member’s death, or may be revoked by the directors upon proof duly made that the member has ceased to be a producer of products handled by or through the association, in the case of producing or selling associations or has ceased to be the user of products handled by or through the association in case of stores and supply associations, or for failure to observe its bylaws or the member’s contractual obligations to it.