(a) Except as provided by Subsections (d) and (e) of this section, Section 814.102, or by rule adopted under Section 813.304(d) or 803.202(a)(2), a member who has service credit in the retirement system is eligible to retire and receive a service retirement annuity if the member:
(1) is at least 60 years old and has at least 5 years of service credit in the employee class; or
(2) has at least 5 years of service credit in the employee class and the sum of the member's age and amount of service credit in the employee class, including months of age and credit, equals or exceeds the number 80.
(b) A member is eligible to retire and receive a service retirement annuity if the member:
(1) is at least 55 years old; and
(2) has at least 10 years of service credit as a:
(A) law enforcement officer; or
(B) custodial officer.
(c) For the sole purpose of determining eligibility to receive a service retirement annuity, the retirement system shall consider service performed as a participant in the optional retirement program under Chapter 830 as if it were service for which credit is established in the retirement system.
(d) Except as provided by Subsection (e) of this section, Section 814.102, or by rule adopted under Section 813.304(d) or 803.202(a)(2), a member who was not a member on the date hired, was hired on or after September 1, 2009, and has service credit in the retirement system is eligible to retire and receive a service retirement annuity if the member:
(1) is at least 65 years old and has at least 10 years of service credit in the employee class; or
(2) has at least 10 years of service credit in the employee class and the sum of the member's age and amount of service credit in the employee class, including months of age and credit, equals or exceeds the number 80.
(e) A member who takes the oath of office for a position included in the elected class of membership, other than a district attorney or criminal district attorney, is not eligible to retire and receive a service retirement annuity under this section that is based on service credit transferred to the employee class from the elected class under Section 813.503 until the member no longer holds that position. This provision does not prohibit a member from retiring and receiving a service retirement annuity under this section that is based on service credit earned in a position included in the employee class of membership under Section 812.003.