When a treatment or service is gender affirming treatment, as defined in RCW 48.43.0128, it is an unfair practice for any health carrier to:

(1) Deny or limit coverage, issue automatic denials of coverage, impose additional cost sharing or other limitations or restrictions on coverage, or deny or limit coverage of a claim, if gender affirming treatment is:

(a) Prescribed to an individual because of, related to, or consistent with a person's gender expression or identity, as defined in RCW 49.60.040;

(b) Medically necessary; and

(c) Prescribed in accordance with accepted standards of care;

(2) Apply blanket exclusions or categorical exclusions to gender affirming treatment; or

(3) When prescribed as medically necessary, exclude facial gender affirming treatment (such as tracheal shaves), hair removal procedures, and other care (such as mastectomies, breast reductions, breast implants, or any combination of gender affirming procedures, including revisions to prior treatment) as cosmetic services.