He led the largest component of the United States Department of Homeland Security, with 42,000 active duty, 8,200 Reserve, 8,000 civilian, and 31,000 Auxiliary personnel.

Papp's assignments ashore have included the Commandant of Cadets staff at the U.S. Coast Guard Academy; Aids to Navigation staff in the Third Coast Guard District; Chief of the Capabilities Branch in the Defense Operations Division; Chief of the Fleet Development Team; Director of the Leadership Development Center; Chief of the Coast Guard's Office of Congressional Affairs; and Deputy Chief of Staff of the Coast Guard.

He served as the operational commander for all U.S. Coast Guard missions within the eastern half of the world; ranging from the Rocky Mountains to the Persian Gulf and spanning an area of responsibility across 42 states with over 14 million square miles, and serving with more than 51,000 military and civilian employees and Auxiliarists.

On 16 July 2014, U.S. Secretary of State John Kerry announced the appointment of retired Admiral Robert Papp to serve as U.S. Special Representative for the Arctic.

Papp is the 13th Gold Ancient Mariner of the Coast Guard, which is an honorary position held by an officer, with the earliest date of qualification as a Cutterman and over ten years of cumulative sea duty.

In a cover story interview published in the February 2012 issue of Military Officer, he described his plans for budgetary reductions in the U.S. Coast Guard.