RCW 51.28.100

The department shall accept the signature of a physician assistant on any certificate, card, form, or other documentation required by the department that the physician assistant's participating physician or physicians, as defined in RCW 18.71A.010, may sign, provided that it is within the physician assistant's scope of practice, and is consistent with the terms of the physician assistant's collaboration agreement as required by chapter 18.71A RCW. Consistent with the terms of this section, the authority of a physician assistant to sign such certificates, cards, forms, or other documentation includes, but is not limited to, the execution of the certificate required in RCW 51.28.020. A physician assistant may not rate a worker's permanent partial disability under RCW 51.32.055.