(CNN) More than 6 million people have signed up for the Affordable Care Act, a number the Obama administration and others have said is needed to make the ACA viable.
There were more than 1.5 million visits to HealthCare.gov and more than 430,000 calls to the call centers on Wednesday.
Health and Human Services Director Kathleen Sebelius has refused to say how many of those who have signed up have actually paid their first deductible.
More than 25 changes have been made to the ACA law and several delays have been issued.
There are still concerns though, the Congressional Budget Office originally predicted 7 million would sign up.and adopted by the administration. But it shows considerable gains from the first month when just 106,000 people had signed up.
Getting younger people to sign up is still a challenge.
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.