Though sweeping regulations helped to clarify many points about the framework needed for state-based health insurance exchanges, experts at actuarial and consulting firm Milliman say there are important questions that still need answers.

The Department of Health and Human Services released Monday 244 pages of proposed rules and details that are to serve as guidelines for states as they build federally required health insurance exchanges that need to be fully operational by 2014.

"The exchange regulations provide clarification on some points while leaving many questions open," says Cathy Murphy-Barron, Milliman principal and consulting actuary. "The possibility that exchanges could serve a larger role in the rate review process introduces questions about interaction between state insurance departments and exchanges."