WASHINGTON — “Obama-care” seems to be holding its own. The administration said Wednesday that 6.4 million people have enrolled for subsidized private coverage through HealthCare.gov, ahead of last year’s pace.

Despite rising premiums, dwindling insurers and the Republican vow to repeal President Barack Obama’s health care law, about 400,000 more people signed up through Monday than for a comparable period in 2015, the Health and Human Services Department said.

“Today’s enrollment numbers confirm that doomsday predictions about the marketplace are not bearing out,” said HHS Secretary Sylvia Burwell.

Still, it’s too early for supporters of the Affordable Care Act to say “I told you so.”

It’s unclear if the administration will meet its target of 13.8 million sign-ups. That’s partly because the share of new customers is down when compared with current consumers re-upping for another year. New customers are 32 percent of the total this year versus 40 percent around the same time last year. Administration officials said they’re going to focus on getting more customers before the end of open enrollment Jan. 31.

Other vital signs for HealthCare.gov were encouraging. “There are zero signs that the ACA’s marketplaces are in danger of imminent collapse,” said Larry Levitt of the nonpartisan Kaiser Family Foundation, who has followed the health care law from its inception.

That carries an implicit warning for President-elect Donald Trump and congressional Republicans, who have promised to move quickly to repeal the law. Although immediate changes affecting 2017 are unlikely, the whole process could take several years, creating uncertainty for people with coverage.

As if on cue, Democratic governors Wednesday fired off a letter to GOP congressional leaders, calling the repeal plan “nothing more than a Washington, D.C., bait-and-switch” that would leave millions uninsured.