Illinois voters will be asked if they support a state law requiring health insurance providers to offer prescription birth control coverage to employees.
Governor Quinn signed a measure Sunday to put the non-binding referendum on the November ballot.
Illinois already requires insurance plans to cover contraceptive drugs for women.
Quinn says the question is important after the U.S. Supreme Court ruled that some private companies can refuse to pay for contraceptives, based on the religious beliefs of its owners.
Republicans call it an election year tactic.