Officials say their plan to save Chicago's pension system from insolvency helps participants by ensuring there's money in the future to pay them, even if annual benefits are cut.
The city plan is to hike property taxes and cut automatic annual benefit increases to reduce a $19.5-billion pension deficit in half over 40 years.
Chicago's attorneys say the 2014 state law does not violate the Constitution's prohibition on public pension benefits being "diminished or impaired" because it requires adequate long-term funding.
Lawyers for city employees who contest the law say the arguments are similar to arguments state officials made last spring before the high court struck down a law that cut benefits to state employee pensions.
The Illinois Supreme Court took the arguments under advisement.
