Two-Year Home Country Physical Requirement
Upon completion of their J-1 Program in the United States, some exchange visitors are required to return to their home country for at least 2 years before they are eligible to change to an H-1B or to apply for permanent resident status. J-1 and their J-2 dependents may be subject to the requirement for any of three reasons:
They received U.S. for foreign-government financing.
Their skills are critically needed skills by their country.
They are foreign medical graduates seeking additional medical training
Its purpose is to have the home country benefit from the Exchange Visitor’s experience in the United States. Exchange Visitors come to this country for a specific objective such as program or study or a research project.
* If you do not know whether your country and/or field appear on the "Exchange Visitor's Skills List," ask at IFSO or check the Department of State website.
http://travel.state.gov/