President Obama announced the milestone Thursday in a call with enrollment counselors and outreach volunteers, who are undertaking an intense marketing drive in the final days of open enrollment. There were more than 1.5 million visits to HealthCare.gov and more than 430,000 calls to the call centers on Wednesday.
Those who've started the application by Monday but are unable to finish because of technical issues will receive more time to complete the process, officials have said.
Reaching 6 million is a symbolic victory for the Obama administration following the botched launch in October. It is short of the initial goal of 7 million, which was based on a projection by the Congressional Budget Office and adopted by the administration. But it shows considerable gains from the first month when just 106,000 people had signed up.
Last month, the CBO revised its projection down to 6 million because of the rocky initial rollout.
But just how many people fully enroll in the program this year remains to be seen. The latest figures reflect those picking plans, not paying their premiums. Only those who pay their first month's premium are considered enrolled, while those who don't pay have their policy selections canceled.
Insurers have said that the share of people sending in payments is in the 80% range.
Also, the total number of enrollees nationwide is not that important a number, experts have said. What's more critical is whether enrollment meets each insurer's expectations since that's what will determine premiums for next year. Insurers are looking at both how many people pick their policies and how many claims they file.
Many experts are watching the share of young adults picking plans since they are considered healthier and less costly than older enrollees. Some 25% of those signing up are between ages 18 to 34, as of the end of February, the latest figures available. The White House and independent experts had forecast about 40% would be young adults.