(1) Small employer exemption (A) In general This section shall not apply to any group health plan for any plan year of a small employer. (B) Small employer For purposes of subparagraph (A), the term “small employer” means, with respect to a calendar year and a plan year, an employer who employed an average of at least 2 (or 1 in the case of an employer residing in a State that permits small groups to include a single individual) but not more than 50 employees on business days during the preceding calendar year. For purposes of the preceding sentence, all persons treated as a single employer under subsection (b), (c), (m), or (o) of section 414 shall be treated as 1 employer and rules similar to rules of subparagraphs (B) and (C) of section 4980D(d)(2) shall apply.
26 USC § 9812(c)(1)
None identified, default scope is assumed to be the parent (subchapter B) of this section.