The Chicago Teachers Union is at odds with the school district over a proposed change to employee retirement plans.

Chicago Public Schools officials say that hiring a central record keeper for the plans will reduce workers' investment costs. But CTU President Marilyn Stewart says district officials are meddling in teachers' financial affairs.

"The one-size-fits-all approach doesn't work in a classroom. It does not work for adults, either," Stewart said during recent Board of Education. "Since the cost of the program is paid entirely by the participants, they should have a lot of say in where their money -- what vendor -- best fits their needs."

The board did not vote on the matter, but could do so at an upcoming meeting.

According to CPS officials, about half of 43,840 employees at the district voluntarily contribute to their 403(b) and 457 plans, which are nonprofit and governmental retirement plans similar a 401(k) plan. Total investments in the district's retirement plans add up to about $1.4 billion.

Employees can choose from six fund managers to invest their contributions, officials say, and workers pay various investment fees based on which funds they select.

Under the district's plan, teachers would be able to invest in the same funds as they currently do.

Investment fees are common among all types of retirement plans, but fund managers vary widely in how much they charge for management and administration. According to Forbes' Investopedia, the average mutual fund carries expenses of 1.3 to 1.5 percent of invested assets.

Part of the expenses are administrative, an area CPS officials targeted when they recommended Great-West Life & Annuity Insurance Co. to handle record keeping and administration. According to district documents, staff selected the Denver company through a competitive bid process.

CPS officials say that with Great-West as a central record keeper, they expect employees who contribute to their retirement plans to save about half a percent in investment fees.

It might seem like chump change, but compounded over 10, 20 and 30 years, the costs can add up to thousands and even tens of thousands of dollars for some investors.

"When you project that out to the average employee here, it means well over $10,000 more at retirement," says Ron Huberman, chief executive officer at the district. "We're doing a terrible disservice to our people right now with the current plan."

Stewart's response to Huberman's warning is that the decision to change the retirement plans should remain in teachers' hands.

"If I get an advisor who's going to charge me an arm and a leg, and that's my crazy choice, you shouldn't be the one to say, Marilyn, you can't do that."