When you agree to participate in an Exchange Visitor Program and your program falls under the conditions explained below, you will be subject to the two-year home-country physical presence (foreign residence) requirement. This means you will be required to return to your home country for two years at the end of your exchange visitor program. This requirement under immigration law is based on Section 212(e) of the Immigration and Nationality Act, as amended, and Title 22 Part 40 and Part 41 in the Code of Federal Regulations.
This requirement does not prohibit a visitor from returning to the US in any other immigration status. For example, if the visitor wishes to return as a tourist or student within the two-year period and meets the requirements for those entries, the two-year physical presence requirement does not prohibit this.
An exchange visitor (and any dependents) are subject to the two-year home country physical presence requirement if any of the following conditions exist:
Change of Status and Waivers of Requirement - If the exchange visitor is subject to the two-year home-country physical presence (foreign residence) requirement, he or she cannot change his/her status until he or she has returned to his/her home country for at least two-years OR received a waiver of that requirement. Such waivers may be requested and if approved, obtained under these five separate bases:
No Objection Statement;
Conrad Program (for physicians), or
Interested Government Agency
For information about waivers, eligibility and process, see Waiver of the J Visa Two-Year Foreign Residence Requirement 212(e).
For information about Advisory Opinions, see https://travel.state.gov/content/visas/en/general/advisory-opinions.html
Other questions might be answered at http://travel.state.gov/content/visas/en/study-exchange/student/residency-waiver/ds-3035-faqs.html