The Government Charge Card Abuse Prevention Act of 2012 (Charge Card Act) requires the Office of Inspector General to conduct an annual risk assessment and periodic audits on agency charge card programs. We conducted this audit to determine whether the Department of Homeland Security implemented internal controls to prevent illegal, improper, and erroneous purchases and payments. During fiscal year 2016, DHS reported spending approximately $1.2 billion in purchase, travel, and fleet card transactions. Although the Department has established internal controls for its charge card programs, the components we reviewed did not always follow DHS’ procedures. Our testing results of purchase, travel, and fleet card transactions revealed internal control weaknesses. Specifically, we found major internal control weaknesses that persisted at the United States Coast Guard and some control weaknesses within CBP’s Fleet Card Program.