Iowa Constitution Art. IV, § 19. Succession to office of governor and lieutenant governor

If there be a vacancy in the office of the governor and the lieutenant governor shall by reason of death, impeachment, resignation, removal from office, or other disability become incapable of performing the duties pertaining to the office of governor, the president of the senate shall act as governor until the vacancy is filled or the disability removed; and if the president of the senate, for any of the above causes, shall be incapable of performing the duties pertaining to the office of governor the same shall devolve upon the speaker of the house of representatives; and if the speaker of the house of representatives, for any of the above causes, shall be incapable of performing the duties of the office of governor, the justices of the supreme court shall convene the general assembly by proclamation and the general assembly shall organize by the election of a president by the senate and a speaker by the house of representatives. The general assembly shall thereupon immediately proceed to the election of a governor and lieutenant governor in joint convention.