Subject to Section 1551.351, on application to the board of trustees and on arrangement for payment of contributions and postage:
(1) an individual who has at least eight years of service credit in the Employees Retirement System of Texas for service as a member of the legislature, on ending the individual's service in the legislature, remains eligible for participation in the group benefits program; and
(2) an individual who has at least 10 years of service credit in the Employees Retirement System of Texas as an employee of the legislature, on ending the individual's service for the legislature, remains eligible for participation in the group benefits program.