For agencies that are part of a hierarchy, you can use the specific agency instead of including the full hierarchy. If you introduce an abbreviation in your first in-text citation, you may use that abbreviation in subsequent citations.
National Heart, Lung, and Blood Institute. (2011). Your guide to anemia (NIH Publication No. 11-7629). http://www.nhlbi.nih.gov/health/public/blood/anemia-yg.pdf
As in-text citation:
First Time: (National Heart, Lung, and Blood Institute [NHLBI], 2011)
All Subsequent Times: (NHLBI, 2011)
Note: if the author and website are the same, omit the website.
Matese, M. A. (1997, March). Accountability-based sanctions (Office of Juvenile Justice and Delinquency Prevention Fact Sheet No. 58). National Criminal Justice Reference Service. https://www.ncjrs.gov/pdffiles/fs-9758.pdf
As in-text citation:
Source: Publication Manual, 10.4 (examples 50-52)