Overall enrollment through state and federal insurance exchanges slowed from January to February, leaving the Department of Health and Human Services about 2 million people shy of its target.

February saw 942,000 sign-ups for health coverage through the Affordable Care Act, down from 1.1 million in January, according to the official enrollment report for the month. That brought total enrollment in private coverage to about 4.2 million a month before the deadline for 2014 enrollment on March 31.

Officials from the Centers for Medicare and Medicaid Services, which is responsible for enrollment, downplayed the slight dip and avoided saying whether they believe the agency will meet its target of 6 million sign-ups. They pointed to past experiences with new health programs, such as the Massachusetts plan that mirrors the Affordable Care Act, arguing enrollment will surge in the days leading up to the close of enrollment.

 “We know that many people use the deadline as an action-forcing event and will come in and enroll in coverage in those last days and weeks,” said Julie Bataille, HHS’ director of communications.

The Congressional Budget Office originally anticipated 7 million people would sign up for coverage through state and federal web sites offering subsidized private insurance and Medicaid for those earning below a certain threshold. But HHS lowered its prediction to 6 million after the faulty rollout of HealthCare.Gov. Experts have said young adults need to account for about 40 percent of new enrollees, or about 2.4 million, to make sure insurance pools aren’t overrun with sickly, more costly people who drive up costs. The figures released Tuesday show HHS has some work to do: 27 percent of sign-ups over the past two months came from the 18-to-34-year-old bracket. 

The figures reported by HHS include people who chose a health plan but didn’t necessarily pay premiums yet, and the agency still maintains its data on that front isn’t accurate enough to release. Bataille predicted the agency would release the number of people who have actually paid for coverage in the “next few months” following the end of open enrollment.

It’s also not clear how many of the 4.2 million were previously uninsured. Some recent surveys have indicated that most people who have signed up were previously insured, but Gallup has continued to report a drop in the uninsured rate.

This story was originally published by Governing magazine.