The Obama administration provided a few details Tuesday about a special enrollment period for Americans who sought to sign up through the online federal health insurance marketplace for coverage starting Jan. 1 but failed to obtain it.

In a blog post under the heading, "Couldn't enroll by December 23? We can still help you get covered," the Centers for Medicare and Medicaid explained that individuals could reach out to a network of federally-sponsored call centers around the country any day this week besides Christmas Day to try to complete their health insurance applications.