For a closed health benefit plan under which a small employer health benefit plan issuer is no longer enrolling new small employers, the issuer shall use the percentage change in the base premium rate to adjust premium rates under Section 1501.206(a)(1). The portion of change in premium rates computed under that subdivision may not exceed, on a percentage basis, the change in the new business premium rate for the most similar health benefit plan under which the issuer is enrolling new small employers.
Tex. Ins. Code § 1501.207