HJR 21 proposes a constitutional amendment that would permit the Texas legislature to expand the circumstances under which a partially disabled veteran or their spouse may qualify for an exemption from ad valorem taxation of part of the market value of the veteran's residence homestead. Currently, the Texas legislature may provide that a partially disabled veteran or their spouse is entitled to an exemption from ad valorem taxation of a percentage of the market value of the disabled veteran's residence homestead only if the residence homestead was donated to the disabled veteran by a charitable organization at no cost to the veteran. The amendment would allow the Texas legislature to provide that the exemption also may be taken when the residence homestead was donated, sold, or transferred to the disabled veteran by a charitable organization for less than the market value of the residence homestead. The amendment also harmonizes certain related provisions of the Texas Constitution.