Iowa Code § 490.1020: Authority to amend.

1. A corporation’s shareholders may amend or repeal the corporation’s bylaws.

2. A corporation’s board of directors may amend or repeal the corporation’s bylaws unless any of the following apply:

a. The articles of incorporation, section 490.1021, or, if applicable, section 490.1022, reserve that power exclusively to the shareholders in whole or part.

b. Except as provided in section 490.206, subsection 4, the shareholders in amending, repealing, or adopting a bylaw expressly provide that the board of directors shall not amend, repeal, or adopt that bylaw.

3. A shareholder of the corporation does not have a vested property right resulting from any provision in the bylaws.