“Self-managed plan”: The defined contribution retirement program maintained under the System as described in Section 15-158.2. The self-managed plan also includes disability benefits as provided in Sections 15-150 through 15-153.3 (but disregarding disability retirement annuities under Section 15-153.2). The self-managed plan does not include retirement annuities, death benefits, or survivors insurance benefits payable directly from the System as provided in Sections 15-135 through 15-149 and Section 15-153.2, or refunds determined under Section 15-154.