Tex. Ins. Code § 1301.052
An insurer offering a preferred provider benefit plan may not refuse a request made by a physician participating as a preferred provider under the plan and an advanced practice nurse or physician assistant to have the advanced practice nurse or physician assistant included as a preferred provider under the plan if:
Added by Acts 2003, 78th Leg., ch. 1274, Sec. 3, eff. April 1, 2005.