29 U.S.C. § 1003: Coverage

by any employer engaged in commerce or in any industry or activity affecting commerce; or by any employee organization or organizations representing employees engaged in commerce or in any industry or activity affecting commerce; or by both. such plan is a governmental plan (as defined in section 1002(32) of this title ); such plan is a church plan (as defined in section 1002(33) of this title ) with respect to which no election has been made under section 410(d) of title 26 ; such plan is maintained solely for the purpose of complying with applicable workmen’s compensation laws or unemployment compensation or disability insurance laws; such plan is maintained outside of the United States primarily for the benefit of persons substantially all of whom are nonresident aliens; or such plan is an excess benefit plan (as defined in section 1002(36) of this title ) and is unfunded. If a pension plan allows an employee to elect to make voluntary employee contributions to accounts and annuities as provided in section 408(q) of title 26 , such accounts and annuities (and contributions thereto) shall not be treated as part of such plan (or as a separate pension plan) for purposes of any provision of this subchapter other than section 1103(c), 1104, or 1105 of this title (relating to exclusive benefit, and fiduciary and co-fiduciary responsibilities) and part 5 of subtitle B of this subchapter 1 (relating to administration and enforcement). Such provisions shall apply to such accounts and annuities in a manner similar to their application to a simplified employee pension under 1 See References in Text note below. section 408(k) of title 26 .