Some states said they will have to make changes to their computer systems after the exchanges come online. Exchanges also might not be fully integrated right away with other federal programs, such as food stamps and housing vouchers.
The states have triaged their responsibilities to make sure they are able to accept applicants on Oct. 1.
“This report highlights the complexity states face in setting up exchanges and how (the Centers for Medicare and Medicaid Services’) workload will increase dramatically in getting exchanges off the ground," Sen. Charles Grassley said in a statement. "The challenges that need to be overcome by October 1, 2013, remain significant.”
The Health and Human Services Department has spent $3.7 billion so far on grants to the 17 states that are setting up their own exchanges.
The healthcare law provides an unlimited budget for those grants, and HHS has said it expects to have spent $5.7 billion on grants by the end of next year.
HHS cannot use that money, however, to set up a federally run exchange in the 33 states that opted not to build their own marketplaces.