(1) A qualified supervisor must be:

(a) Credentialed as a sex offender treatment provider under this chapter. The credential must be in good standing without pending disciplinary action; or

(b) A person who meets the requirements for certification as a sex offender treatment provider; or

(c) A person who meets a lifetime experience threshold under RCW 18.155.020 and who continues to maintain professional involvement in the field.

(2) A qualified supervisor not credentialed by the department as a sex offender treatment provider must sign and submit an attestation form provided by the department.