(1) ((All))Except as provided in subsection (3) of this section, all claims for exemption shall be made and signed under oath by the person entitled to the exemption, by his or her attorney-in-fact or in the event the residence of such person is under mortgage or purchase contract requiring accumulation of reserves out of which the holder of the mortgage or contract is required to pay real estate taxes, by such holder or by the owner((, either before two witnesses or the county assessor or his or her deputy in the county where the real property is located)): PROVIDED, That if a claim for exemption is made by a person living in a cooperative housing association, corporation, or partnership, such claim shall be made and signed by the person entitled to the exemption and by the authorized agent of such cooperative.

(2) If the taxpayer is unable to submit his or her own claim, the claim shall be submitted by a duly authorized agent or by a guardian or other person charged with the care of the person or property of such taxpayer.

(3) All claims for exemption and renewal applications shall be accompanied by such documented verification of income as shall be prescribed by rule adopted by the department of revenue.

(5) The tax liability of a cooperative housing association, corporation, or partnership shall be reduced by the amount of tax exemption to which a claimant residing therein is entitled and such cooperative shall reduce any amount owed by the claimant to the cooperative by such exact amount of tax exemption or, if no amount be owed, the cooperative shall make payment to the claimant of such exact amount of exemption.

(6) A remainderman or other person who would have otherwise paid the tax on real property that is the subject of an exemption granted under RCW 84.36.381 for an estate for life shall reduce the amount which would have been payable by the life tenant to the remainderman or other person to the extent of the exemption. If no amount is owed or separately stated as an obligation between these persons, the remainderman or other person shall make payment to the life tenant in the exact amount of the exemption.

(1) A claim for exemption under RCW 84.36.381 as now or hereafter amended, may be made and filed at any time during the year for exemption from taxes payable the following year and thereafter and solely upon forms as prescribed and furnished by the department of revenue. However, an exemption from tax under RCW 84.36.381 continues for no more than six years unless a renewal application is filed as provided in subsection (3) of this section.

(2) A person granted an exemption under RCW 84.36.381 must inform the county assessor of any change in status affecting the person's entitlement to the exemption on forms prescribed and furnished by the department of revenue.

(3) Each person exempt from taxes under RCW 84.36.381 in 1993 and thereafter must file with the county assessor a renewal application not later than December 31 of the year the assessor notifies such person of the requirement to file the renewal application. Renewal applications must be on forms prescribed and furnished by the department of revenue.

(4) At least once every six years, the county assessor must notify those persons receiving an exemption from taxes under RCW 84.36.381 of the requirement to file a renewal application. The county assessor may also require a renewal application following an amendment of the income requirements set forth in RCW 84.36.381.

(5) If the assessor finds that the applicant does not meet the qualifications as set forth in RCW 84.36.381, as now or hereafter amended, the claim or exemption must be denied but such denial is subject to appeal under the provisions of RCW 84.48.010 and in accordance with the provisions of RCW 84.40.038. If the applicant had received exemption in prior years based on erroneous information, the taxes must be collected subject to penalties as provided in RCW 84.40.130 for a period of not to exceed five years, except that the repayment period must be for up to two years where the error occurred prior to 2025 and is based on the applicant occupying the property as the applicant's principal residence for more than six months, but less than nine months, of the year.

(6) The department and each local assessor is hereby directed to publicize the qualifications and manner of making claims under RCW 84.36.381 through 84.36.389, through communications media, including such paid advertisements or notices as it deems appropriate. Notice of the qualifications, method of making applications, the penalties for not reporting a change in status, and availability of further information must be included on or with property tax statements and revaluation notices for all residential property including mobile homes, except rental properties.

(8) Beginning August 1, 2019, and by March 1st every fifth year thereafter, the department must publish updated income thresholds. The adjusted thresholds must be rounded up to the nearest one thousand dollars. If the income threshold adjustment is negative, the income threshold for the prior year continues to apply. The department must adjust income thresholds for each county to reflect the most recent year available of estimated county median household incomes, including preliminary estimates or projections, as published by the office of financial management. For the purposes of this subsection, "county median household income" has the same meaning as provided in RCW 84.36.383.

(9) Beginning with the adjustment made by March 1, 2024, as provided in subsection (8) of this section, and every second adjustment thereafter, if an income threshold in a county is not adjusted based on percentage of county median income, then the income threshold must be adjusted based on the growth of the consumer price index for all urban consumers (CPI-U) for the prior twelve month period as published by the United States bureau of labor statistics. In no case may the adjustment be greater than one percent. The adjusted thresholds must be rounded to the nearest one dollar. If the income threshold adjustment is negative, the income threshold for the prior year continues to apply.