The Michigan Court of Appeals ruled on Friday that ballots have to arrive by November 3 in order to count in the election.
The court ruled unanimously that any changes must come from the legislature.
Court of Claims Judge Cynthia Stephens had previously ruled that ballots postmarked November 2 had 14-days to arrive.
Attorney General Dana Nessel and Secretary of State Jocelyn Benson are leaving it up to the Legislature to make any changes and will not appeal the case.