The number of enrolled still falls short of the 3.3 million the Obama administration was hoping for. Joe Raedle/Getty Images

Over 2 million people have enrolled in health insurance plans through the federally run HealthCare.gov and state healthcare websites since enrollment began in October, U.S. officials said on Tuesday.

While the numbers of enrollees fall short of the 3.3 million enrollees the Obama administration was hoping for by the end of year, the number is a dramatic improvement from the early weeks of the program when barely 150,000 signed up for coverage through HealthCare.gov because of a series of technical problems.

HealthCare.gov covers 36 states; another 14 states have their own websites.

Sign-ups for what has become known as "Obamacare" picked up during December as the website's performance improved, and as more Americans focused on getting coverage by the new year.

Many of the newly insured under the "Patient Protection and Affordable Care Act" enrolled just ahead of a Dec. 24 deadline to receive benefits on Jan. 1, giving health insurers a tight framework to create accounts that can be accessed by doctors. The Obama administration was alerted to HealthCare.gov's problems as early as March, and the site crashed soon after its launch on Oct. 1, as millions of visitors entered the site, and remained balky for much of the ensuing weeks.

The problem-plagued rollout disappointed those who were trying to enroll in subsidized health insurance and damaged the credibility of President Obama and his signature domestic policy achievement. Two officials have left the U.S. agency that was in charge of launching the website.

Administration officials hope they have now turned a corner toward a better-working program that makes it possible for millions of Americans to get health insurance who did not have it before. People can still sign up until March 31 for coverage in 2014.

But the new year is expected to bring new challenges as many Americans begin to use their medical coverage for the first time.

"January 1st marks not only the beginning of a New Year but an exciting new day in health care as millions of Americans will now be able to access care, thanks to the coverage they found at the Health Insurance Marketplace," Health and Human Services Secretary Kathleen Sebelius said in a blog posting on Tuesday.

"For many of the newly insured ... it will be the first time that they can enjoy the security that comes with health coverage," Sebelius said. She said the administration was doing everything possible to help with the transition period.

Al Jazeera and Reuters