Program providers are a network of universities that offer study abroad programs in various countries. Most have an academic mandate and adhere to U.S. academic standards. Many also have U.S. based main offices and on-site staff that can assist students with enrollment, finding housing, acquiring entry clearance, and navigating through the host country and culture.
Though there are program providers in Korea, they may not be quite as useful as they would be in other countries. Korean universities can easily accommodate foreign students that aren't fluent in the local language thereby reducing the need for a third party to run interference between the student and the host university.
AsiaLearn  at Korea University in Seoul
CIEE  at Yonsei University in Seoul
USAC  at Yonsei University in Seoul