The articles of incorporation of every hospital service plan corporation, and amendments thereto, shall be submitted to the director, whose approval thereof shall be endorsed thereon before the same are filed with the secretary of state; provided, however, that if the articles of incorporation of any such corporation shall have been filed with the secretary of state prior to July 1, 1966, the approval thereof by the director shall be evidenced by a separate instrument in writing filed with the secretary of state.
SDCL 58-40-2