IRS attempts to clarify scope of employer health insurance mandate for variable-hours employees

The Affordable Care Act requires employers with 50 or more employees to provide full-time employees with health insurance coverage or face a tax penalty. This rule sounds straightforward, but what should an employer do if it cannot readily determine whether an employee will work full time? The IRS recently attempted to resolve this confusion by clarifying how to determine whether variable-hour employees work full or part time, and by establishing a safe harbor for employees whose status is not known at their time of hire.