qualified preretirement survivor annuity
(2) Special rule for defined contribution plans In the case of any defined contribution plan or participant described in clause (ii) or (iii) of section 401(a)(11)(B), the term “qualified preretirement survivor annuity” means an annuity for the life of the surviving spouse the actuarial equivalent of which is not less than 50 percent of the portion of the account balance of the participant (as of the date of death) to which the participant had a nonforfeitable right (within the meaning of section 411(a) ).