Even states that are solidly committed to pursuing an exchange are facing major logistical challenges in building the computer systems that will be able to handle enrollment when exchanges open for business in 2014. That's largely because the system that will actually connect people to the right coverage will have to "talk" to many other systems, and the systems don't use a common language. This includes a yet-to-be built federal "data hub" with tax and citizenship info, the enrollment systems of multiple private insurers selling exchange plans and—hardest of all—state Medicaid enrollment systems, many of which are not yet fully computerized.