SPRINGFIELD, Ill. (AP) -- Standard & Poor's Ratings Services has changed its outlook on Illinois' credit rating for the worse.
The agency Wednesday revised its outlook from "developing" to "negative" on Illinois' A-minus rating.
S&P says the state's $35.7 billion budget isn't structurally balanced. It also cites an Illinois Supreme Court ruling that found the state can't force retirees to pay for part of their health care.
The case is seen as a possible indicator of how the court will rule on a challenge to the statewide pension overhaul approved last year.
S&P says if the pension overhaul is found unconstitutional it could have a "profound and negative effect on Illinois' budgetary performance and liquidity."
Gov. Pat Quinn's budget office says the move is a "predictable result" from the Legislature passing an "incomplete budget."