The chief judge of the Circuit Court of Cook County, Ill., issued an order on Monday that bail-reform advocates hope will be a turning point in the national controversy over requiring defendants to pay more money than they can afford in order to be set free on bail before their trials.

The judge, Timothy C. Evans, announced that judges in Chicago could still set bail to ensure that defendants appear in court. But they will be required to determine whether the “defendant has the present ability to pay the amount necessary.” In other words, it will no longer be possible to set bail so high that people do not have enough money to pay for their release, which could mean they remain in jail for months or even years before a trial, a plea bargain or a dismissal.

Under the order, judges in Chicago will still be allowed to release defendants on their pledge to appear for their court date — or to deny bail altogether because of flight risk or danger to the community.

Judge Evans’s order is an effort to ameliorate what critics say is one of the most glaring inequities in the criminal justice system: the ability of defendants with more money to post bail and avoid jail time.