ATLANTA - The federal government's insurance exchange will begin operating on its scheduled start date of Oct. 1, a senior federal health administrator said this week after the state's top health official predicted it would not.

The conflicting messages came during a half-day conference on health reform hosted by the Georgia Chamber of Commerce. They illustrate the level of uncertainty about implementation of the most sweeping government program in a generation. The exchange is where individuals can shop for coverage from one of six companies and apply for a federal subsidy to pay part of the premiums under the Affordable Care Act that's also called ObamaCare.

"We'll start on time. I'm not worried about starting on time," said Marilyn Tavenner, administrator of the U.S. Centers for Medicare & Medicaid Services. "This may not be a perfect plan, but it is the plan that's going forward."