(a) An independent school district may elect to participate as a small employer without regard to the number of employees in the district. An independent school district that makes the election is treated as a small employer under this chapter for all purposes.
(b) An independent school district that is participating in the uniform group coverage program established under Chapter 1579 may not participate in the small employer market under this section for health insurance coverage and may not renew a health insurance contract obtained in accordance with this section after the date on which the program of coverages provided under Chapter 1579 is implemented. This subsection does not affect a contract for the provision of optional coverages not included in a health benefit plan under this chapter.