Texas Insurance Code - INS § 4151.154. Discount Health Care Programs

(1) accept or process a claim for prescription drugs under a discount health care program as defined by Section 7001.001 unless the pharmacist or pharmacy agrees in writing to accept or process the claim;

(2) participate in a specified provider network as a condition of processing a claim for prescription drugs under a discount health care program;  or

(3) participate in, or process claims under, a discount health care program as a condition of participation in a provider network.