The authority conferred under a power of attorney created prior to January 1, 2017, and also for a power of attorney created on or after January 1, 2017, terminates upon the incapacity of the principal unless the writing contains the words "This power of attorney shall not be affected by disability of the principal," or "This power of attorney shall become effective upon the disability of the principal," or similar words showing the intent of the principal that the authority conferred shall be exercisable notwithstanding the principal's incapacity.
RCW 11.125.040