Unions had persuaded a judge to freeze an Oct. 26 deadline for teachers to make crucial decisions on contributions to the system. State officials asked the Supreme Court to intervene and undo that restraining order, but justices said they will let the case run its course in lower courts.
The lone dissenter Friday was Justice Stephen Markman, who said the state has made a strong showing that the retirement system will suffer financial losses if changes approved by Gov. Rick Snyder are delayed.
Snyder signed a law in September that overhauls the retirement system and requires teachers to pay to retain certain benefits. Those changes are being challenged in court.