Tex. Insurance Code § 1251.254

Except as provided by this section, an employee, member, or dependent who elects to continue group coverage under this subchapter must pay to the employer or group policyholder each month the amount of contribution required by the employer or policyholder, plus two percent of the group rate for the coverage being continued under the group policy. A payment under this section must be made not later than the 45th day after the date of the initial election for coverage and on the due date of each payment thereafter. Following the first payment made after the initial election for coverage, the payment of any other premium shall be considered timely if made on or before the 30th day after the date on which the payment is due.