President Barack Obama challenged Long Beach and 19 other cities across the nation this week to increase the number of residents insured under the Affordable Care Act during the open enrollment period.

In an interview Friday, Mayor Robert Garcia accepted the challenge. The winning city will get a visit from the president.

Problem is, arriving at an exact number of uninsured residents in the city proper is hard to come by.

According to a press release sent by the White House, there are 480,000 people in Long Beach “and the surrounding region” who are uninsured and eligible under Covered California. When asked for clarification, White House officials referred calls to the state Health and Human Services Department, which referred calls to Covered California, which provided the number of enrollees in its program, but not the number of uninsured.

The most recent data of uninsured from the city’s Health and Human Services Department is from 2013. The city at that time reported 22.3 percent of the population did not have insurance, which amounted to almost 105,000 people.

As of June, an estimated 12,420 Long Beach residents have signed up and paid for coverage under Covered California, according to the state agency.

Regardless, city officials say they look forward to enrolling more residents and competing with other cities, which include Oakland, Atlanta, Las Vegas and Seattle.

“What they’re basically looking for are larger areas that have the best opportunity to increase their enrollment and that have the best infrastructure to help them improve enrollment,” Garcia said. “We’re convening with our health department, which will obviously be taking the lead in our efforts, but we also have great community partners; educators, hospitals and we’ll be reaching out to our communities and our community leaders to help.”

Lisa Rubino, a spokeswoman for Long Beach-based Molina Healthcare, said the issue of coverage is often confusing for residents, with so many options and plans available. Many people don’t know what benefits they qualify for, how much insurance they can afford, or that they could have the majority of their coverage paid for through subsidies, she said.

Continuous outreach is needed to educate communities about health care coverage available to them, Rubino said. That means teaming with a variety of groups, including charitable organizations, faith-based communities and schools.

“It’s a multipronged approach, and it usually is a multivisit communication,” Rubino.

Obama urged such a push in his letter, sent this week to the Press-Telegram editorial board.

“So maybe you’re a local official, a pastor, or a sports hero who can spread the word,” Obama said. “Maybe you’ve got a cousin or an uncle who’s been uninsured for far too long. Or maybe you’re between jobs and don’t think that affordable coverage is an option for you. No matter who you are, everybody can get covered or help their neighbors do so.”

The White House said they are challenging communities “that collectively include a significant number of the remaining uninsured and represent particularly high opportunity for impact due to geography, infrastructure and ongoing enrollment efforts.”

Garcia acknowledged the political division in the country over the Affordable Care Act.

“I know there are people who have issues with that, and I get that,” he said. “But it’s here and it’s certainly in our benefit to make sure people are insured. Absolutely it’s a good thing, because having a healthy community makes for a stronger community.”

And there should be a healthy battle between the city and Oakland, the only other California town in the challenge.

“I’m sure I’ll at least have a side competition with the mayor of Oakland (Libby Schaaf), because she’s a good friend and we’re both very competitive,” he said.

The White House said with open enrollment underway, sign-ups by Dec. 15 mean people will have coverage by the new year. Open enrollment ends Jan. 31.

Residents may sign up at CoveredCA.com, or call 800-300-1506, a toll-free number for assistance.

Tim Grobaty contributed to this report.