From the White House:

“Health care should be a right, not a privilege. But for many Americans caught in the so-called “family glitch,” the peace of mind that health insurance brings has remained out of reach. Because of this glitch, employer-based health insurance has been considered “affordable” if the coverage is affordable for the employee even if it is not for their family members—making those family members ineligible for Affordable Care Act subsidies even though they need them to afford quality coverage.
 
In April, I announced that we were proposing to fix this regulatory flaw. Now, the Treasury Department is finalizing that fix so that the law works the way Congress intended and the cost of coverage comes down for families all over the country. Starting next month, Americans can sign up to take advantage of this change. About 1 million Americans will either gain coverage or see their insurance become more affordable as a result of the new rule. This marks the most significant administrative action to implement the Affordable Care Act since the law was first put into place. It builds on our progress so far, which has brought the rate of uninsured Americans to a record-low eight percent.”