S.C. Code Ann. § 12-6-1190: Cost recovery of retirement benefits from retirement systems maintained by the State or its political subdivisions.

Retirees receiving benefits from the various state retirement systems or any other retirement plan maintained by a political subdivision of this State who have recovered all or a part of their recoverable costs in their retirement benefits for federal income tax purposes before January 1, 1989, are considered to have recovered those costs for purposes of the state income tax. For taxable years beginning after 1988, cost recovery of these retirement benefits is the same for both state and federal income tax purposes.