The Health and Human Services Department said the site improved after it was taken offline for improvements over the weekend, and more work is scheduled to begin at 1 a.m. Tuesday.
Carney said wait times on the website had been "reduced by a third" after the implementation of a "waiting room" that staggers applicants' access to the system. The press secretary also said the administration was "adding server capacity" and "making software changes" to aid the process.
Consumers have six months to sign up for coverage, and October was not expected to be a big month for enrollment. Still, especially low enrollment in the first month could feed into GOP criticisms that the law is "not ready for prime time."