(16) Employer. The term
employer means the person that is the employer of an employee under the common-law standard. See
§ 31.3121(d)-1(c). For purposes of determining whether an employer is an applicable large employer, all persons treated as a single employer under
section 414(b), (c), (m), or (o) are treated as a single employer. Thus, all employees of a controlled group of entities under
section 414(b) or (c), an affiliated service group under
section 414(m), or an entity in an arrangement described under
section 414(o), are taken into account in determining whether the members of the controlled group or affiliated service group together are an applicable large employer. For purposes of determining applicable large employer status, the term
employer also includes a predecessor employer (see
paragraph (a)(36) of this section) and a successor employer.