Civilian retirees - 40,000 - $ 454,938,448
U.S. Postal Service - 27,807 - $ 283,365,996
Homeland Security - 4,856 - $ 37,012,174
Health and Human Services (Welfare) - 2,841 - $ 37,327,491
Federal Deposit Insurance Corporation - 155 - $ 2,249,326
Executive Office of the President - 41 - $ 831,055
Justice - 1,971 - $ 14,350,152
The full list of delinquencies by agency department available here:
http://yidwithlid.blogspot.com/2010/09/scofflaws-irs-reports-federal-employees.html