Ind. Code § 5-10.2-5-9

Sec. 9. 1980 Cost of Living Adjustment. As a cost of living increase, the retirement, disability, and survivor benefits payable after June 30, 1980, to a member, or a beneficiary or a survivor of a member, who retired before August 1, 1979, shall be increased four percent (4%). The increase provided by this section is in addition to any other increase provided by law. This section does not apply to benefits payable in a lump sum.