The (Springfield) State Journal-Register reports that the money is being held in escrow with retirees continuing to pay into the special state account.
The court's July 3 ruling reversed a lower court decision to dismiss a challenge to a government move forcing employees to pay for part of their own health care.
The justices will formally return the case to the lower court Aug. 7. The court will also decide on how the money is going to be returned.
The case is seen as a possible indicator of how the court will rule on a wider challenge to a statewide pension overhaul approved last year.