Tex. Labor Code § 408.128: COMMUTATION OF IMPAIRMENT INCOME BENEFITS.

(a) An employee may elect to commute the remainder of the impairment income benefits to which the employee is entitled if the employee has returned to work for at least three months, earning at least 80 percent of the employee's average weekly wage.

(b) An employee who elects to commute impairment income benefits is not entitled to additional income benefits for the compensable injury.

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