Obama administration officials say about 476,000 health insurance applications have been filed through new "Obamacare" exchanges.
That's the most detailed measure yet of the problem-plagued rollout of President Barack Obama's signature legislation.
However, the officials continue to refuse to say how many people have actually enrolled in the insurance markets.
(Read more: Obamacare: Contract for troubled site swells)
Without enrollment figures, it's unclear whether the program is on track to reach the 7 million people projected by the Congressional Budget Office to gain coverage during the six-month sign-up period.
The officials did not want to be cited by name and would not discuss the health insurance rollout unless they were granted anonymity.