By Rachana Pradhan | POLITCO

The number of Americans insured under Obamacare fell by nearly 2 million people between Jan. 31 and mid-March, according to new CMS data that found about 10.3 million still were covered through health law exchanges.

The decline reflects customers failing to pay premiums after they selected plans during the most recent open enrollment period. Roughly 12.2 million people had selected private plans through the federal HealthCare.gov exchanges and the state-run marketplaces that operate in about a dozen states as of the Jan. 31 deadline to sign up.

CMS said high costs and lack of affordability were the most common factors individuals cited when asked why they didn’t keep their coverage. A separate report on enrollment trends attributed the drop-off to other factors, including securing a job with employer-sponsored insurance.

The 10.3 million covered individuals include those who selected a plan that began in January or February and had paid their first month’s premium.

Enrollment attrition also occurred during the Obama administration, though reporting periods varied. Roughly 11.1 million people were enrolled in Obamacare plans at the end of March 2016, down from the 12.7 million people who signed up during the previous enrollment period.

The new report comes amid continued troubling news about health law insurance markets, including Anthem’s decision this month to pull out of Ohio’s Obamacare marketplace, potentially leaving 10,500 customers in 18 counties without any insurance options for 2018. Republicans in Congress have cited coverage gaps and other problems as justification for repealing the health law.

Sign-ups for Obamacare coverage declined for the first time in the 2017 season and fell below the Obama administration’s estimates for the three-month enrollment window that ended in January, according to federal data.

The Trump administration scrapped phone calls and other forms of outreach to encourage sign-ups in the finals days of the enrollment period, then reversed itself after the move sparked outcry from the law’s supporters and health insurers. Officials said they were unable to pull back some HealthCare.gov radio and TV advertising that had been purchased by the Obama administration. HHS was able to cancel about $4 million to $5 million in ads.