29 U.S.C. § 1081: Coverage

an employee welfare benefit plan; an insurance contract plan described in subsection (b); a plan which is unfunded and is maintained by an employer primarily for the purpose of providing deferred compensation for a select group of management or highly compensated employees; a plan which is established and maintained by a society, order, or association described in section 501(c)(8) or (9) of title 26, if no part of the contributions to or under such plan are made by employers of participants in such plan; or a trust described in section 501(c)(18) of title 26 ; a plan which has not at any time after September 2, 1974 , provided for employer contributions; an agreement providing payments to a retired partner or deceased partner or a deceased partner’s successor in interest as described in section 736 of title 26 ; an individual retirement account or annuity as described in section 408(a) of title 26 , or a retirement bond described in section 409 of title 26 (as effective for obligations issued before January 1, 1984 ); an individual account plan (other than a money purchase plan) and a defined benefit plan to the extent it is treated as an individual account plan (other than a money purchase plan) under section 1002(35)(B) of this title ; an excess benefit plan; or any plan, fund or program under which an employer, all of whose stock is directly or indirectly owned by employees, former employees or their beneficiaries, proposes through an unfunded arrangement to compensate retired employees for benefits which were forfeited by such employees under a pension plan maintained by a former employer prior to the date such pension plan became subject to this chapter. the plan is funded exclusively by the purchase of individual insurance contracts, such contracts provide for level annual premium payments to be paid extending not later than the retirement age for each individual participating in the plan, and commencing with the date the individual became a participant in the plan (or, in the case of an increase in benefits, commencing at the time such increase became effective), benefits provided by the plan are equal to the benefits provided under each contract at normal retirement age under the plan and are guaranteed by an insurance carrier (licensed under the laws of a State to do business with the plan) to the extent premiums have been paid, premiums payable for the plan year, and all prior plan years under such contracts have been paid before lapse or there is reinstatement of the policy, no rights under such contracts have been subject to a security interest at any time during the plan year, and no policy loans are outstanding at any time during the plan year. This part applies, with respect to a terminated multiemployer plan to which section 1321 of this title applies, until the last day of the plan year in which the plan terminates, within the meaning of section 1341a(a)(2) of this title . The amendments made by this section [enacting section 1084 of this title and amending this section] shall apply to plan years beginning after 2007. If the Secretary of the Treasury grants an extension under section 304 of the Employee Retirement Income Security Act of 1974 [ 29 U.S.C. 1084 ] and section 412(e) of the Internal Revenue Code of 1986 [former 26 U.S.C. 412(e) ] with respect to any application filed with the Secretary of the Treasury on or before June 30, 2005 , the extension (and any modification thereof) shall be applied and administered under the rules of such sections as in effect before the enactment of this Act [ Aug. 17, 2006 ], including the use of the rate of interest determined under section 6621(b) of such Code [ 26 U.S.C. 6621(b) ].”