(a) Except as provided by Subsection (b), a farm mutual insurance company may write insurance in:
(1) the county in which the company’s home office is located at the time of incorporation and in any county adjoining the county in and for which the company is organized;
(2) any county in which another farm mutual insurance company is not organized; and
(3) any county in this state if the company’s reserve fund exceeds $200,000 in cash or securities in which the reserve fund of a stock fire insurance company may be invested.
(b) This section does not apply to a farm mutual insurance company organized and operating in this state under a certificate of authority issued before May 21, 1973, under former Chapter 16 of this code.