The U.S. Health and Human Services Department estimates that 1 million more people will sign up for health insurance on the Obamacare exchanges for 2017 compared with 2016, a department official told reporters on Wednesday.

President Barack Obama's Affordable Care Act, often called Obamacare, created online exchanges where consumers can shop for individual health insurance and receive income-based subsidies. The exchanges opened in 2014 with insurance for sale by major companies including Aetna Inc and Anthem Inc.

But enrollment has been about half of what was initially expected and some large insurers this year have said they were losing too much money on the exchanges because of that and the fact that enrollees are older and sicker than expected. Aetna and UnitedHealth Group have largely pulled out of the exchanges for 2017.

The health department said it expects 2017 sign-ups of 13.8 million people versus 12.7 million for 2016. Average monthly enrollment in 2017 is estimated at 11.4 million people, up from 10.5 million people in 2016, the official said.

Separately, Health and Human Services Secretary Sylvia Burwell told reporters there are 10.7 million uninsured people who are eligible for the exchanges, and that about 40 percent of those are young. More enrollees in that group, aged 18 to 34, could help balance out insurer costs because they typically have lower health costs.

This article was provided by Reuters.