Possibly. Companies that are members of a controlled group are aggregated together for purposes of determining whether collectively they are large enough to be subject to the “play-or-pay” rules under the ACA (also known as the employer mandate).

Because the controlled group has more than 100 employees, each separate company in the controlled group is subject to the “play-or-pay” rules, even if each company is not large enough to be subject to the rules on its own. However, liability is determined separately for purposes of whether any company in the controlled group owes a “play-or-pay” penalty tax. So, for example, if the company does not offer health insurance to its employees, but it does not have a full-time employee who receives a premium tax credit from the federal government, then the company will not owe any penalty tax.

Conversely, if the company does not offer health insurance to its employees and at least one of the company's full-time employees enrolls in a health plan purchased through a health insurance exchange and receives a premium tax credit from the federal government, then it will be subject to a penalty tax under the “play-or-pay” rules.

Source: Questions and Answers on Employer Shared Responsibility Provisions Under the Affordable Care Act, http://www.irs.gov/Affordable-Care-Act/Employers/Questions-and-Answers-on-Employer-Shared-Responsibility-Provisions-Under-the-Affordable-Care-Act.