Yes, the Affordable Care Act requires large employers to provide coverage to full-time employees or pay a penalty. This provision, called the “play or pay” rule, goes into effect Jan. 1, 2014. Small employers – those with fewer than 50 employees – are exempt from the coverage requirement and penalty.
As a side note, be aware that the ACA uses different definitions of “large employer” for different provisions of the overall law. While any company with 50 or more employees is considered large for the play-or-pay rule, the more frequently used definition is a business that maintains an average of 100 employees over the course of a year.