Tex. Labor Code § 408.021: ENTITLEMENT TO MEDICAL BENEFITS.

(a) An employee who sustains a compensable injury is entitled to all health care reasonably required by the nature of the injury as and when needed. The employee is specifically entitled to health care that:

(1) cures or relieves the effects naturally resulting from the compensable injury;

(2) promotes recovery; or

(3) enhances the ability of the employee to return to or retain employment.

(b) Medical benefits are payable from the date of the compensable injury.

(c) Except in an emergency, all health care must be approved or recommended by the employee's treating doctor.

(d) An insurance carrier's liability for medical benefits may not be limited or terminated by agreement or settlement.

Acts 1993, 73rd Leg., ch. 269, Sec. 1, eff. Sept. 1, 1993.