WASHINGTON — Sign-ups under President Obama’s health care law surged last week, driven by a deadline for getting covered by Jan. 1, officials said Tuesday. Unlike last year, the HealthCare.gov website was working well.

More than 1 million people picked a plan from Dec. 6 through Dec. 12, bringing the total to nearly 2.5 million, said Health and Human Services officials.

“It’s been a strong start,” said Andy Slavitt, overseeing the second-year rollout. “Our call center and our technology have done their jobs – so far.”

Tuesday’s numbers were partial, really just a subtotal. They reflected the 37 states served by HealthCare.gov. Enrollment for states running their own websites will be reported later. And Tuesday’s numbers also did not include totals from the weekend and Monday, which saw strong consumer interest.

The administration has set an overall goal of 9.1 million people signed up for 2015. That includes new customers plus roughly 6.7 million current customers, most of whom will be renewed automatically.

That goal could well be exceeded after this year’s promising start.

Avalere Health, a private market analysis firm, estimated Tuesday that enrollment will total 10.5 million people by the end of 2015.