COLUMBUS, Ohio — Columbus City Schools employees could face sharply higher health insurance premiums or reduced coverage if the district and the Columbus Education Association do not resolve a dispute by Wednesday’s deadline. District projections show that costs could rise by as much as $550 per person each month, depending on the plan an employee chooses. The changes would take effect Jan. 1, with open enrollment scheduled to begin Oct. 5. The Columbus Education Association represents about 4,500 district employees. Union President John Coneglio said educators should not be forced to absorb the cost of what he described as district mismanagement. “If this district wants to make academic gains, then they need to take care of the people who take care of kids,” Coneglio said. “We have the right to take care of our children, too.” The conflict centers on the district’s health insurance benefits program and its relationship with consultant Aon. An audit discussed publicly in August found that the district may have overspent as much as $40 million because of what the union called a flawed agreement with the consultant. The union is urging the district to pursue legal action against Aon and seek recovery of taxpayer money. Coneglio said employees should pay for the care they use, but not for costs resulting from the district’s decisions. “We are willing to pay what we use, but we’re not going to pay for the district’s screw-up and their mismanagement of our health care,” he said. In a statement, the district disputed the union’s characterization of the spending. Columbus City Schools said expenses associated with the Aon agreement were not lost or misspent, and that reserved funds covered the costs rather than charging them to employees. The district also said health care expenses are rising nationally and locally, and argued that the union is responsible for proposing changes that would address those increases and prevent employee surcharges. District officials said they have sought a solution since March. Coneglio said the union has not received the financial information it needs to evaluate proposed changes. He also accused the district of refusing to hold Aon accountable. The union filed a grievance in late August over the district’s arrangement with Aon. It has asked the district to delay open enrollment so negotiations can continue, but district officials said changes made after Wednesday would not prevent the higher rates scheduled for January. The deadline is tied to the need to provide employees with plan information before open enrollment begins. The union is holding public events this week to explain the dispute and its potential financial impact on school employees.