The State newspaper reported Gov. Mark Sanford called a summit to discuss the problem.
The Budget and Control Board estimates the shortfall at $12 billion. Sanford thinks it's much higher.
Aiken Sen. Greg Ryberg says he thinks the shortfall is between $20 billion and $30 billion. He expects lawmakers to work on the problem next year.
The retirement system covers 232,000 active state and local government employees and another 118,000 retirees in five plans.
Alternatives include cutting benefits, raising the number of years for workers to retire from 28 years to 30 years. Lawmakers could also change the way benefits are calculated.