(Adds new customers, background)
WASHINGTON, Dec 6 (Reuters) - The number of people signing up for 2018 Obamacare plans picked up significantly during the fifth week of open enrollment, a U.S. government agency reported on Wednesday, but the number of people signed up for such plans appears to be falling short of last year's numbers with just over a week of enrollment left.
The U.S. Department of Health and Human Services said 823,180 people signed up for 2018 Obamacare individual insurance in the 39 states that use the federal government website Healthcare.gov for the week ended Dec. 2, up from 504,181 people in the previous week. About 3.6 million people so far have signed up for Obamacare plans using the federal website.
New consumer sign-ups rose to 271,207 from 152,243 during the previous week.
The Trump administration halved the Obamacare open enrollment period for 2018 to six weeks ending Dec. 15, and cut the healthcare law's advertising budget by 90 percent. In 2017, more than 9.2 million consumers signed up for insurance plans using Healthcare.gov during the 12-week open enrollment period, which includes people who were automatically re-enrolled at the close of the enrollment period.
The figures do not include enrollment in Washington, D.C., or the 11 states that run their own enrollment and websites, some of which have enrollment periods that are weeks longer. The subsidized individual insurance market is part of former President Barack Obama's healthcare law, commonly known as Obamacare. (Reporting by Yasmeen Abutaleb; Editing by Jonathan Oatis and David Gregorio)