(1) A worker may be certified as a preferred worker, in the sole discretion of the supervisor of industrial insurance or the supervisor's designee, if the worker has an open state fund insured claim for an industrial injury or occupational disease, or a closed state fund claim where the closure is not final, that results in a permanent disability which may be a substantial obstacle to employment.

(2) For purposes of subsection (1) of this section, permanent disability is defined as:

(a) A permanent loss of physical or mental function, causally related to the industrial injury or occupational disease, from which, within the limits of medical probability, further recovery is not expected; and

(b) The injured worker's health care provider has permanently restricted the worker from returning to the job of injury; and

(c) The work restrictions in (b) of this subsection are supported by medical findings appropriate to the worker's physical or mental condition.

(3) For purposes of subsection (1) of this section, "substantial obstacle to employment" means one or more of the following limitations apply:

(a) The worker is unable to perform at least one of the essential functions of the job of injury;

(b) The department finds the worker eligible for vocational retraining;

(c) The worker is permanently restricted to a lighter category of physical work demands; for example, a worker previously able to perform heavy work is permanently restricted to sedentary or light work.

(4) The preferred worker certification is assigned to the worker, and the preferred worker incentives are available to any qualified employer who may hire the worker during the preferred worker certification period.