WASHINGTON — About 1.6 million people who signed up for coverage this year under President Barack Obama’s health care law dropped out by the end of March, according to administration figures released Thursday.

The report from the Health and Human Services department said some 11.1 million people were still signed up. But that’s a drop of nearly 13 percent from the 12.7 million who initially enrolled for subsidized private coverage this year. Those dropouts failed to seal the deal by paying their premiums.

The pattern of attrition is not new, and has been seen each year since customers began receiving health law coverage in 2014.

However, this year the administration had been trying to do a better job of weeding out problem applications while sign-up season was still under way.