§ 4006.6 Definition of “participant.”
(a) General rule. For purposes of this part and part 4007 of this chapter, an individual is considered to be a participant in a plan on any date if the plan has benefit liabilities with respect to the individual on that date.
(b) Loss or distribution of benefit. For purposes of this section, an individual is treated as no longer being a participant—
(1) In the case of an individual with no vested accrued benefit, after—
(i) The individual incurs a one-year break in service under the terms of the plan,
(ii) The individual's entire “zero-dollar” vested accrued benefit is deemed distributed under the terms of the plan, or
(iii) The individual dies; and
(2) In the case of a living individual whose accrued benefit is fully or partially vested, or a deceased individual whose accrued benefit was fully or partially vested at the time of death, after—
(i) An insurer makes an irrevocable commitment to pay all benefit liabilities with respect to the individual, or