‘‘Member’’ defined; membership optional; calculation. Employee and employer contributions. Service retirement allowance. Conditions; rights, privileges, obligations, and duties. Disability retirement; periodic medical examination and review. Death allowances and benefits. Withdrawal; employer contributions; vesting; date of election. Impact on members of Employees’ Retirement System of Georgia on December 31, 2008. Conflicting provisions. Administration. pensation plans for employees of state, § 45-18-30 et seq. Provision that exclusion from classified service shall not exclude any employee, officer, or official from membership in Employees’ Retirement System of Georgia, § 45-20-6(c).