Texas Government Code - GOV'T § 814.003. Effective Date of Retirement

(a) The effective date of a member's service retirement is the date the member designates at the time the member applies for retirement as provided by Section 814.101, but the date must be the last day of a calendar month.

(b) If a person elects to receive a standard service retirement annuity and dies during the first calendar month that begins after the effective date of the person's retirement, the person is considered to have been a contributing member at the time of death.

(c) The retirement system may allow an applicant for retirement time after the effective date of the person's retirement to make a selection of a retirement annuity.  If the applicant dies within the time allowed without having given the retirement system notice of a selection, the person is considered to have been a contributing member at the time of death.

(d) The effective date of a member's disability retirement is the date designated on the application for retirement filed by or for the member as provided by Section 814.201, but the date must be the last day of a calendar month.

(e) If a person elects to receive a standard disability retirement annuity and dies during the first calendar month that begins after the effective date of the person's retirement, the person is considered to have been a contributing member at the time of death.