Wash. Rev. Code § 49.76.040
(2) When an employee requests leave under RCW 49.76.030 or requests a reasonable safety accommodation under RCW 49.76.115 the employer may require that the request be supported by verification that:
(4) An employee may satisfy the verification requirement of this section by providing the employer with one or more of the following:
(8)
(b) Information given by an employee may be disclosed by an employer only if:
[ 2018 c 47 s 3; 2008 c 286 s 4.]