WASHINGTON — Milwaukee, Detroit and Philadelphia have done the best among 20 cities competing to sign up people for health insurance under the Affordable Care Act, while Dallas, Denver and Las Vegas are lagging, the White House said Monday ahead of Tuesday’s deadline to enroll for coverage that takes effect on Jan. 1.
A surge of callers temporarily overwhelmed the government’s capacity to enroll consumers on Monday, prompting officials to record telephone numbers so they could return calls later to arrange for coverage.
Federal officials said that people stuck waiting would be given a brief special enrollment period so they could complete their applications and select health plans after Dec. 15, but still get coverage in January.
"We are seeing unprecedented demand," said Lori Lodes, a spokeswoman for the Department of Health and Human Services, which runs the federal insurance marketplace.
But successes do vary. In early November, President Obama challenged 20 communities around the country to compete with one another in signing up people who were uninsured. The places were chosen because they had large numbers of uninsured residents or because people lacking coverage accounted for a large share of the population.
A scoreboard prepared by the White House says that Milwaukee — with a Democratic mayor who strongly supports the health law — has made the most progress, followed by Detroit, Philadelphia, Chicago, Charlotte, N.C., and Atlanta. Oakland, Calif., Nashville, Tampa, Fla., and Salt Lake City were also in the top 10.
Dallas, Denver, Las Vegas, New Orleans, Phoenix and Great Falls, Mont., did less well, but are "still in the game," the Obama administration said Monday.
Not everyone is on board. A news release on Nov. 6 from the Obama administration said that Mayor Michael J. Winters of Great Falls had "embraced the Healthy Communities Challenge."
Mr. Winters, in an interview Monday, was less than enthusiastic.
"It's not something we want to be involved in," said the mayor, a Republican completing his third term. "If the White House wants to push its agenda, they should do it without our participation."
Mr. Winters said White House officials had reached out to him. "They were rather pushy about it, borderline rude," he said. "Montanans don't appreciate people calling us and being rude to us on the phone."
The White House had no immediate comment. Bob Kelly, a city commissioner who is to become mayor of Great Falls in January, said that despite the views of Mr. Winters, "there is a coalition of health care providers and organizations holding enrollment events and publicizing opportunities for coverage here."
Administration officials declined to provide enrollment data for the 20 cities they said were participating in the president's Healthy Communities Challenge.
Mayor Tom Barrett of Milwaukee, a Democrat who served in the House of Representatives from 1993 to 2003, made sure his city helped people enroll at health insurance fairs and included information about open enrollment in residents' water bills.
Enrollment is open through Jan. 31. People who go without insurance next year may be subject to tax penalties of $695 a person or more, although some may qualify for exemptions.
People can apply for insurance online, at HealthCare.gov, or by calling the federal marketplace at 800-318-2596.
Federal officials have encouraged consumers who have coverage to return to the marketplace and shop for insurance for 2016. People who do not do so will, in many cases, be automatically re-enrolled in the same or similar plans, although the premiums, subsidies and other details of coverage may be different.
Andrew M. Slavitt, the acting administrator of the Centers for Medicare and Medicaid Services, which runs the federal marketplace, said that HealthCare.gov was handling "record traffic" on Monday, with 178,000 people using the site at 2:30 p.m., higher than the number of users at any other point this year or last year.
As of June 30, about 9.9 million people had coverage through the federal and state marketplaces, and more than four out of five of them were receiving subsidies to help pay their premiums.
Sylvia Mathews Burwell, the secretary of health and human services, has said she expects 10 million people to have coverage through the federal and state marketplaces at the end of 2016.