Iowa Code § 496C.12
No professional corporation shall create or issue any securities convertible into shares of the professional corporation. The provisions of this chapter with respect to the issuance and transfer of shares and disposal of treasury shares apply to the creation, issuance, and transfer of any rights or options entitling the holder to purchase from a professional corporation any shares of the corporation, including treasury shares. Rights or options shall not be transferable, whether voluntarily, involuntarily, by operation of law, or in any other manner. Upon the death of the holder, or whenever the holder ceases to be licensed to practice in this state a profession which the corporation is authorized to practice, the rights or options shall expire.
Iowa Code § 496C.12