The U.S. Government Accountability Office serves as an independent organization that tracks federal government spending. It produces a large number of reports annually. The sixth edition of "Publication Manual of the American Psychological Association" provides format guidelines for citing material from government-related agencies such as the GAO.
When including information from a GAO report in your writing, use an in-text citation. After the material, put "Government Accountability Office" without quotation marks, a comma and the publication year of the report in parentheses. If the office's name in within the text, omit it from the parentheses. If there are subsequent citations, use the office's abbreviation. Approach this in one of two ways. If the office's name is included in the text, all reference citations should contain GAO and the year. If the office has not been mentioned in the text, list the full name of the office, [GAO], a comma and the year within parentheses the first time the office is cited; for example: (Government Accountability Office, [GAO], 2011). Subsequent citations include just the abbreviation, comma and date within parentheses.
If you cite a GAO report in the text, include it on the "References" page. Begin with the full name of the office and a period. Put the publication year within parentheses. Add a period. Include the italicized name of the report in sentence case. Within parentheses put the publication number. Add a period. Finish with the publication information: "Washington, D.C.: U.S. Government Printing Office" without quotation marks and a period; for example: Government Accountability Office. (2013). Two USDA agencies can enhance safeguards against project duplication and strengthen collaborative planning. (GAO Publication No. 13-255). Washington, D.C.: U.S. Government Printing Office.