Fourteen U.S. states and the District of Columbia so far have told the federal government they plan to operate healthcare exchanges under President Barack Obama's reform law, leaving Washington with the daunting task of creating online marketplaces for at least two-thirds of the country.

On the eve of a federal deadline for states to say whether they will run their own exchanges, a top U.S. healthcare policy official told lawmakers that the exchanges will start enrolling eligible families starting on Oct. 1, 2013.

"I am confident that states and the federal government will be ready in ten months, when consumers in all states can begin to apply," Gary Cohen, director of the Center for Consumer Information and Insurance Oversight, told a health oversight panel in the U.S. House of Representatives.