Washington Revised Code Title 4. Civil Procedure § 4.16.350. Action for injuries resulting from health care or related services--Physicians, dentists, nurses, etc.--Hospitals, clinics, nursing homes, etc.

(1) A person licensed by this state to provide health care or related services, including, but not limited to, a physician, osteopathic physician, dentist, nurse, optometrist, podiatric physician and surgeon, chiropractor, physical therapist, psychologist, pharmacist, optician, physician's assistant, osteopathic physician's assistant, nurse practitioner, or physician's trained mobile intensive care paramedic, including, in the event such person is deceased, his or her estate or personal representative;

(2) An employee or agent of a person described in subsection (1) of this section, acting in the course and scope of his or her employment, including, in the event such employee or agent is deceased, his or her estate or personal representative;  or

(3) An entity, whether or not incorporated, facility, or institution employing one or more persons described in subsection (1) of this section, including, but not limited to, a hospital, clinic, health maintenance organization, or nursing home;  or an officer, director, employee, or agent thereof acting in the course and scope of his or her employment, including, in the event such officer, director, employee, or agent is deceased, his or her estate or personal representative;  based upon alleged professional negligence shall be commenced within three years of the act or omission alleged to have caused the injury or condition, or one year of the time the patient or his or her representative discovered or reasonably should have discovered that the injury or condition was caused by said act or omission, whichever period expires later, except that in no event shall an action be commenced more than eight years after said act or omission:  PROVIDED, That the time for commencement of an action is tolled upon proof of fraud, intentional concealment, or the presence of a foreign body not intended to have a therapeutic or diagnostic purpose or effect, until the date the patient or the patient's representative has actual knowledge of the act of fraud or concealment, or of the presence of the foreign body;  the patient or the patient's representative has one year from the date of the actual knowledge in which to commence a civil action for damages.

For purposes of this section, notwithstanding RCW 4.16.190, the knowledge of a custodial parent or guardian shall be imputed to a person under the age of eighteen years, and such imputed knowledge shall operate to bar the claim of such minor to the same extent that the claim of an adult would be barred under this section.  Any action not commenced in accordance with this section shall be barred.

For purposes of this section, with respect to care provided after June 25, 1976, and before August 1, 1986, the knowledge of a custodial parent or guardian shall be imputed as of April 29, 1987, to persons under the age of eighteen years.

This section does not apply to a civil action based on intentional conduct brought against those individuals or entities specified in this section by a person for recovery of damages for injury occurring as a result of childhood sexual abuse as defined in RCW 4.16.340(5).