D.C. Code § 47-1069: American Psychological Association, lot 146, square 677.

The real estate described for assessment and taxation purposes as lot 146, square 677, in the District of Columbia, and the buildings located thereon, owned by APA 750 LLC, a wholly-owned subsidiary of the American Psychological Association, a District of Columbia nonprofit corporation, is hereby exempt from taxation for that portion of property owned by APA 750 LLC and occupied and used by the American Psychological Association to the extent that the property continues to be so owned and occupied, and not used for commercial purposes, subject to the provisions of §§ 47-1007 and 47-1009.