"If you had asked me a year ago whether enrollment for 2018 would be almost equal to 2017, I would have laughed at you," said Larry Levitt, who follows the health law for the nonpartisan Kaiser Family Foundation.
Total enrollment remained remarkably stable despite Trump's disdain for "Obamacare," and multiple attempts by the Republican-led Congress to repeal it.
"These results show that people recognize how important coverage is for their health and financial stability," said Kristine Grow of America's Health Insurance Plans, the industry lobby.
Newly confirmed Health and Human Services Secretary Alex Azar is a critic of the health law but has avoided directly antagonizing Democrats over it.
The Trump administration is trying to address that by promoting lower-cost insurance alternatives that don't offer the comprehensive benefits available through the health law.
For example, people who lose employer coverage may not know the health law offers them an option.
Health law enrollment peaked at 12.7 million for 2016 and has declined every year since them. »