The call centers now handling many individuals' enrollment applications under the Affordable Care Act have received more than a million calls, Health and Human Services Secretary Kathleen Sebelius told CNN Tuesday night.

"The call centers are open for business. We’ve had a million, one hundred thousand calls," Sebelius to CNN host Sanjay Gupta, who is a doctor. She added that people can sign up for health insurance under the federal marketplaces as well. "So people are able to sign up."