(1) In all determinations, cases, and appeals adjudicated under Title 50A RCW the employment security department is an "interested party."

(2) Other interested parties in paid family or medical leave determinations related to the state plan and appeals include:

(a) The employee or former employee; and

(b) An employer or former employer of that employee that is required to provide information to the department related to the determination or appeal in question.

(3) Other interested parties in paid family or medical leave determinations related to an approved voluntary plan include:

(a) The employer or former employer; and

(b) An employee or former employee.

(4) The department may designate an employee or employer as an interested party in other determinations made by the department.