S&P Global Ratings revised the outlook to negative from stable and affirmed its'A'long-term rating on Cook County School District No. 170 (Chicago Heights), Illinois'general obligation (GO) debt. The negative outlook reflects an at least one-in-three chance we could lower the rating if expenditure reductions are not sufficient to narrow recurring deficits, resulting in reserves that no longer support the rating. The series 2017C and 2017D limited-tax bonds are secured by the district's ad valorem property tax levy, which is unlimited as to rate but limited as to amount, based on the district's debt service extension base (DSEB). Debt service is within the existing DSEB, assuming no growth. We rate the limited-tax bonds at the same level as
