The “Affordable Care Act” requires “large” employers – those with 50 or more full-time-equivalent employees – to either provide “qualified” health coverage for all of their full-time employees, or pay an annual penalty of $2,000 per full-time employee (after the first 30) if they don’t provide such coverage. If they do provide coverage but it’s not “affordable,” the penalty is $3,000 per employee who finds it “unaffordable” (with a cap at the penalty they’d pay for not offering coverage at all).
“Full-time” is defined as 30 hours or more per week, or 120 hours or more per month. (“Affordable” is defined as less than 9.5% of the employee’s family income.)
The penalty is assessed on a monthly basis. In other words, if an employee works 121 hours in a given calendar month, that 121st hour costs the employer $166.67 (one-twelfth of $2,000), in addition to the employee’s pay for that hour and the payroll tax on that amount. That’s a hefty charge, and it’s much more than the hourly rate typical for part-time employment in most industries.
If the employer decided to let the employees work more than 30 hours (and pay the penalty), the money to pay the penalty would have to come from somewhere. It could come from reduced profits, higher prices – or lower pay for workers. Many business run at very slim profit margins, so it’s unlikely that they could take the entire hit to their profit and stay in business. Business‘ ability to raise prices is limited by customers’ willingness to pay. Chances are, employees would have to absorb some of the penalty – perhaps most of it – in the form of lower wages.
Why Obamacare Incentivizes Part-Time Jobs - Forbes