Enrollment under the Affordable Care Act in 39 states has surged at least 47 percent compared to the same period last year, according to the Centers for Medicare and Medicaid Services.

Nearly 1.5 million Americans signed up for coverage during the first 11 days of enrollment, CMS said Tuesday, including 876,788 during the second week. That compares to just over 1 million Americans who signed up through HealthCare.gov during the first 12 days of open enrollment in 2016.

The portion of new consumers enrolling in ACA plans is slightly down this year, according to the latest federal report. Those Americans accounted for 23 percent of enrollees between Nov. 1 and Nov. 11, as opposed to 24 percent in the early days of 2016.

The new report does not include the dozen or so states, and the District of Columbia, that run their own health-care exchanges. But the vast majority of these states have also seen an uptick in sign-ups as well as call center demand.

Health experts said it is too soon to say what is driving the increase in enrollment, and whether it will be sustained over the course of the 45-day enrollment window. The Trump administration has cut the period for sign-ups in half compared to previous years, and some state and health industry officials have expressed concern that this will mean less time for younger, healthier consumers — who tend to procrastinate in buying coverage — to enroll.

And it comes as Senate Republicans are seeking to eliminate the federal mandate that U.S. taxpayers provide proof of health-care coverage as part of a broader tax bill, which the Congressional Budget Office has estimated would reduce the number of insured Americans by about 13 million over a decade.

Eilperin, Juliet “ACA federal enrollment surges by at least 47 percent this year, CMS says” The Washington Post, November 15th 2017