Vox - Back in 2014, the Congressional Budget Office estimated that 22 million people would be enrolled in the marketplaces by 2016. In reality, the marketplaces have attracted 10.4 million people.Obamacare’s lower-than-expected enrollment drives a lot of the problems we’re seeing right now. It helps explain why many insurers have left the marketplace: The small number of customers makes it a less appealing place to invest resources... “We’ve got all of the sickest people, who are highest need, and they enrolled in 2014,” says Caroline Pearson, a senior vice president at the research firm Avalere Health. “Each year, the marketplaces have continued to not pick up enough healthy people to create a stable risk pool.”
NY Times - Most people are unaffected by the rate increases because they get their insurance through an employer or are covered through government programs like Medicare, Medicaid or the Department of Veterans Affairs. Only a small fraction of Americans who have insurance buy individual policies. There are about 10 million people in the Obamacare markets and around an additional seven million who buy health plans outside the marketplace, according to Obama administration estimates. The published rate increases apply only to people who shop in the markets, but premiums are expected to go up sharply for the other plans as well.