HHS has estimated 13.8 million people will purchase coverage on Affordable Care Act (ACA) insurance exchanges during the next open enrollment period.

The estimate is above what Standard and Poor’s (S&P's) predicted in its Oct. 13 analysis. It expects 11.7 million and 13.3 million people to buy a plan during open enrollment, with as few as 10.2 million people maintaining coverage throughout 2015 as part of a “significant slowdown” in marketplace growth.

“We’re confident that millions of Americans will choose to enroll when they learn that quality, affordable health insurance is within reach,” HHS Secretary Sylvia Burwell said. “We believe 13.8 million sign-ups during the upcoming Open Enrollment will help keep driving down the national uninsured rate, which is already the lowest in our nation’s history.”

The 13.8 million sign-ups would be an increase of 1.1 million over 2016 open enrollment. The agency’s effectuated enrollment estimate was also above S&P’s at 11.4 million.

The gains, Burwell said, could come from several populations, like the estimated 2.5 million off-exchange customers eligible for subsidies if they used the ACA marketplace. The agency has also detailed several new efforts to reach out to younger, healthier customers this year.

“Of course, the biggest opportunity we have to strengthen the marketplace with a bigger, healthier risk pool is right in front of us—this upcoming open enrollment,” Burwell said. "This is the last open enrollment for this administration. We want to make it count."

S&P had factored these efforts into its analysis, while warning enrollment could fall even lower than its estimate if fewer subsidized customers than expected re-enroll for 2017.