Tex. Occupations Code § 151.056

(a) A person who is physically located in another jurisdiction but who, through the use of any medium, including an electronic medium, performs an act that is part of a patient care service initiated in this state, including the taking of an x-ray examination or the preparation of pathological material for examination, and that would affect the diagnosis or treatment of the patient, is considered to be engaged in the practice of medicine in this state and is subject to appropriate regulation by the board.

(b) This section does not apply to the act of:

(1) a medical specialist located in another jurisdiction who provides only episodic consultation services on request to a physician licensed in this state who practices in the same medical specialty;

(2) a physician located in another jurisdiction who is providing consultation services to a medical school as defined by Section 61.501, Education Code;

(3) a physician located in another jurisdiction who is providing consultation services to an institution subject to:

(A) Subchapter C, Chapter 73, Education Code; or

(B) Subchapter K, Chapter 74, Education Code; or

(4) a physician located in another jurisdiction of a state having borders contiguous with the borders of this state who is the treating physician of a patient and orders home health or hospice services for a resident of this state to be delivered by a home and community support services agency licensed in this state.