(1)(a) Except as provided in (b) of this subsection, when calculating an enrollee's contribution to any applicable cost-sharing or out-of-pocket maximum, a health carrier offering a nongrandfathered health plan with a pharmacy benefit, or a health care benefit manager administering benefits for the health carrier, shall include any cost-sharing amounts paid by the enrollee directly or on behalf of the enrollee by another person for a covered prescription drug that is:

(i) Without a generic equivalent or a therapeutic equivalent preferred under the health plan's formulary;

(ii) With a generic equivalent or a therapeutic equivalent preferred under the health plan's formulary where the enrollee has obtained access to the drug through:

(A) Prior authorization;

(B) Step therapy; or

(C) The prescription drug exception request process under RCW 48.43.420; or

(iii) With a generic equivalent or therapeutic equivalent preferred under the health plan's formulary, throughout an exception request process under RCW 48.43.420, including any appeal of a denial of an exception request. If the health carrier utilizes a health care benefit manager to approve or deny exception requests, the exception request process for the purposes of this subsection (1)(a)(iii) also includes any time between the completion of the exception request process, including any appeal of a denial, and when the health care benefit manager communicates the status of the request to the health carrier.

(b) When calculating an enrollee's contribution to any applicable deductible, any amount paid on behalf of the enrollee by another person for a prescription drug that is not subject to payment of a deductible need not be included in the calculation, unless the terms of the enrollee's health plan require inclusion.

(2) Any cost-sharing amounts paid directly by or on behalf of the enrollee by another person for a covered prescription drug under subsection (1) of this section shall be applied towards the enrollee's applicable cost-sharing or out-of-pocket maximum in full at the time it is rendered.

(3) The commissioner may adopt any rules necessary to implement this section.

(4) This section applies to nongrandfathered health plans issued or renewed on or after January 1, 2023.

(5) This section does not apply to a qualifying health plan for a health savings account to the extent necessary to preserve the enrollee's ability to claim tax exempt contributions and withdrawals from the enrollee's health savings account under internal revenue service laws, regulations, and guidance.

(6) For purposes of this section:

(a) "Health care benefit manager" has the same meaning as in RCW 48.200.020.

(b) "Person" has the same meaning as in RCW 48.01.070.