Are small employers required to comply with the ACA Employer Mandate?

Only large employers are required to comply with the Employer Mandate.

Only "large employers" are required to comply with the Employer Mandate. Generally speaking, large employers are employers that had an average of 50 or more full-time or full-time equivalent employees during the preceding year. "Full-time employees" include all employees who work at least 30 hours on average each week. The number of "full-time equivalent employees" is determined by aggregating the hours worked by all non-full-time employees. In determining large employer status, certain related employers under common control or ownership are considered to be a single employer.

While large employer status is determined based on counting the full-time employees and full-time equivalents of all members of a group of related employers under common control or ownership, whether any penalty is owed and the amount of such penalty is calculated separately for each related employer.