Department of Labor
http://www.dol.gov/

Internal Revenue Service
http://www.irs.ustreas.gov/prod/tax_edu/faq/faq13-4.html

Office of Graduate Studies
http://www.usm.edu/graduatestudies/

Social Security Administration
http://www.ssa.gov/

United States Citizenship and Immigration Services (USCIS)
http://www.uscis.gov/portal/site/uscis

United States Department of State
http://www.state.gov/