Some 12.2 million people purchased health insurance through the Affordable Care Act (ACA) exchanges in the last open enrollment period, half a million fewer than in the 2016 and well below the 13.8 million projected by HHS under the Obama administration.

Previous figures released by CMS showed enrollment on the federally facilitated marketplace, Healthcare.gov, had declined from 9.6 million to 9.2 million enrollees this year. The updated figures include numbers from state-run exchanges, some of which did have more higher enrollment individually, but overall enrollment on state marketplaces declined by 100,000, to 3 million customers for 2017.

Of the 12.2 million who signed up, about 3.8 million were new customers, 5.2 million were active re-enrollees who picked another plan and nearly 2.8 million were automatically re-enrolled.

The number of new enrollees are one of several areas which fall short of what Obama’s HHS had projected. It had expected 4.6 million new customers along with 9.2 million returning ones. Despite publicized efforts to recruit more young people to improve the exchanges’ risk pool, only 27 percent (3.3 million) of enrollees were between 18 and 34 years old, down slightly from the group’s 28 percent share in prior open enrollment periods.

Some of that drop-off may be attributed to the Trump administration’s move to pull TV ads in the final days of open enrollment, with younger customers tending to make up most of those last-minute shoppers.

Less optimistic analysts were closer to predicting the final numbers. Standard and Poor’s had estimated total enrollment for 2017 would fall between 11.7 million and 13.3 million.

For 2018, open enrollment could go much differently. For one, the Trump administration has proposed cutting the period in half, ending it on Dec. 15 rather than Jan. 31. Additionally, more insurers could opt out of participating on the exchanges with the proposed American Health Care Act (AHCA) allowing customers to use tax credits on off-exchange coverage.