Employers may face heavy fines if they fail to comply with the "Employer Shared Responsibility" provisions of the Obamacare.  Fines could go as high as $2000 per employee.

Here is the dreaded provision:

Under the Employer Shared Responsibility provisions, if these employers do not offer affordable health coverage that provides a minimum level of coverage to their full-time employees (and their dependents), the employer may be subject to an Employer Shared Responsibility payment if at least one of its full-time employees receives a premium tax credit for purchasing individual coverage on one of the new Affordable Insurance Exchanges, also called a Health Insurance Marketplace (Marketplace).

More at https://www.recruiter.com/i/for-staffing-companies-the-acas-employer-mandate-can-be-downright-baffling/