A University of Georgia health policy expert said Tuesday she doesn’t see the Affordable Care Act taking effect Jan. 1, 2014, because of time-consuming work involved in setting up health care exchanges, or marketplaces for private insurance. “In order for that to happen, open enrollment has to occur in October 2013,” said Phaedra S. Corso, a Gainesville resident who teaches in UGA’s Department of Health Policy and Management. “I don’t see any possible way that our state — or many states — is going to be prepared for that.