U.S. Health and Human Services Secretary Sylvia Burwell visited Atlanta on Friday to support efforts to sign up more people during the health insurance exchange’s open enrollment period.

Burwell, at an enrollment assistance center, noted that Atlanta is in a challenge competition with 19 other cities to sign up the most uninsured people into the exchanges, which were created under the Affordable Care Act.

The 20 cities have high percentages of uninsured consumers eligible for the exchange coverage, and they also feature “engaged stakeholders and leadership,” Burwell said.

The winning city — with the biggest percentage increase in enrollees — gets a visit from President Obama.

HHS estimates that more than 300,000 uninsured people in the Atlanta area qualify for coverage through the exchange, which offers subsidies for the vast majority of potential enrollees.

Burwell was met at the Luckie Street storefront enrollment site by state House Minority Leader Stacey Abrams (D-Atlanta), Fulton County Commission Chairman John Eaves, and HHS Regional Director Pamela Roshell, among others.

Open enrollment for the exchanges started Nov. 1 and runs through Jan. 31. But for coverage that starts Jan. 1, consumers need to enroll by Dec. 15.  The federal government runs Georgia’s exchange.

Burwell chatted Friday with insurance counselors at the enrollment center run by SRA, asking questions and emphasizing the financial assistance available with subsidies for many uninsured.

“We want everyone to shop’’ for the best coverage, she said.

HHS estimates that in Georgia, 96 percent of exchange consumers who switch to the lowest-cost plan within a coverage level could save on average $57 per month, or $683 per year, on their premium costs in 2016.

Other cities involved in the challenge are Kansas City, Milwaukee, Charlotte, Nashville, Chicago, New Orleans, Dallas, Oakland, Calif., Denver, Philadelphia, Detroit, Phoenix, Great Falls, Mont., Richmond, Va., Salt Lake City, Las Vegas, Seattle, Long Beach, Calif., and Tampa.