Mo. Rev. Stat. § 380.231: Company operations limited to Missouri.

1. Any company operating under the provisions of sections 380.201 to 380.591 may do business throughout the state of Missouri but may not do business outside this state. The counties the company proposes to do business in shall be specified in its articles of incorporation and in the certificate of authority issued by the director.

2. All such companies must maintain a membership of at least one hundred members.

3. The name of any such company shall not be deceptively similar to any other insurance company authorized to do business in this state.