The Chicago Public Library system plans to eliminate late fees starting Oct. 1. — making Chicago the largest city in the nation to adopt the growing trend.

Not only will the move do away with late fees going forward, it will also erase all outstanding overdue fees currently owed to the city.

“I think our staff members are going to be practically jumping over their circulation desks to tell people that fines have been eliminated,” Chicago Public Library Commissioner Andrea Telli said.

“We’re removing one of the most important barriers to access,” she said.

The measure, part of a series of library reforms that will officially be announced Monday, seeks to bring equity to a system that for years has locked out library users when they accrue $10 worth of fines — a penalty that disproportionately affects poor families who need free access to books and high-speed internet the most.

“It turns out that particularly in Chicago in the communities that aren’t as socio-economically well off, people are blocked from using libraries from that $10 fine, and as you move north in the city that is not as evident,” Telli said.

One of every three library card holders in the library’s South District — everything south 59th Street — is locked out. In the North District — an area north of North Avenue — only one in six card holders are locked out, according to library officials.

Also, one in five cards that are blocked in Chicago belong to kids under the age of 14.

There are currently 343,208 users locked out due to overdue fines.

“In many cases, people simply never return to their libraries because of this — so we lose the fine, the patron and the material, but the fine is really the most unimportant part,” Telli said.

The change is expected to result in the return of thousands of patrons, along with thousands of long overdue library books.

“Today we are taking a step in the right direction to help our library system once again serve as a gathering place for the entire community, regardless of your financial status,” Mayor Lori Lightfoot said in a statement.

“The data clearly shows that late fines are not effective in promoting the return of books or increasing the number of residents in compliance, while locking many community members out of the library system,” she said. “Building on our efforts to reform Chicago’s historically regressive fines and fees systems, we will bring those who need access the most back into the library system instead of driving them away.”

More than $3.9 million in late fees is owed. The amount the library system actually collected annually — but will no longer — is about $875,000.

The money won’t effect the library’s bottom line because for years it went back into the city’s general revenue fund.

Also beginning in October, checked out items will automatically be renewed up to 15 times — three weeks per renewal.

One week after the final due date, items will be marked as “lost” and accounts will be charged market-price replacement costs. But those costs can been canceled by simply returning the item, or an exact replacement of the original item — brand new is preferred to used.

In order to get locked out, users will have to surpass a $30 dollar threshold of lost items.

There are a few exceptions to these new rules.

Automatic renewals will be interrupted if another library user places a hold (essentially a reservation) on an item.

And items on loan from other library systems, as well as Museum Passports (which allow free admission to Chicago museums), will still be subject to overdue fines.

Telli said the idea was first raised about a year ago when Tony Powers, a branch manager at a Northwest Side library, presented the idea at an annual professional development day.

“It garnered a lot of interest,” Telli said. “He presented his idea while Brian Bannon was still commissioner, and then as the administration changed, and with Mayor Lightfoot’s platform of equity and inclusion, it just seemed like the stars were in alignment.”

The idea took hold at Lightfoot’s first cabinet meeting as mayor.

Asked about critics who may see the move as a blow to personal responsibility, Telli responded: “Libraries don’t necessarily want to be in the morality business, and we don’t want to make the assumption that if a book is late or someone can’t pay for a fine, that they’re delinquent or bad in some way; they may just be in a place in their life where they can’t pay the fine.”

Library officials pointed to previous amnesty periods — two-week windows during which users could eliminate outstanding fines by simply returning overdue books — to highlight the effectiveness of leniency.

During a 2012 amnesty, the library received 101,301 overdue items valued at approximately $2 million. It also waived $641,820 worth of fines and picked up 29,500 users who either renewed or applied for library cards. One of the books that made its way home had been overdue since 1934.

The most recent fine amnesty in 2016 resulted in the return of more than $800,000 worth of library materials, as well as more than 15,000 card renewals and new card holders.

Chicago follows other big cities such as Denver, Salt Lake City, Baltimore, San Francisco and San Diego in eliminating overdue fees.