美国J1和H1签证的区别？
先占个位，等有时间了补充一下 先来介绍下美国签证的分类： A1 A2 B1 B2 F1 F2 J1 J2 H1 H4 L1 L2 O1 O2 P1 P3 Q1 Q3 R1 R2 TN TS TR TPS US 这是美国移民法（Immigration and Nationality Act， I-N-A）里规定的各个签证类别及代码。
目前比较常用的就是B1/B2(观光旅行者)和F1/F2 (留学生及其家属)， 而US是特别为奥巴马总统的移民改革计划而设立的。 下面我将以表格的形式将各种签证进行详细的罗列、解释以及区分 一： 非移民类签证 1.A Nonimmigrant Visa A1， A2 Nonquota Immigrant Visas A1. President's Skilled Worker Program for Foreign Physicians (P-1) This visa was created to help solve the problem of shortage of doctors in rural areas， especially those with an under-supply or lack of access as defined by the U.S. Department of Agriculture. The program allows physicians who are legal permanent residents of foreign nations a temporary， nonrenewable two-year visa to practice medicine in these underserved regions. To qualify this physician must be able to show that he has passed qualifying licensing exams required by states to obtain medical licensure; has completed at least one year of postgraduate training in his field; and is coming to work full time in an area designated by USDA as medically underserved. A2. Refugee (R) Refugees are people being persecuted， or fearing persecution because of race， religion， nationality， membership in a particular social group ， or political opinion. Persecution is defined as torture， inhumane treatment which could kill or cause death， and severe injury to body or health. Refugees apply directly from their home countries through refugee resettlement agencies to the State Department. Once approved， they receive either an immigrant or nonimmigrant visa based on where they may safely settle when arriving in the United States and have their applications processed outside of our borders upon arrival. In general however refugees cannot self-petition， so will need the assistance of a qualified representative such as a lawyer to file on their behalf. Most applicants come from Somalia， Vietnam， Afghanistan and Iraq. Refugees are not allowed employment during the first 18 months after admission into the US； thereafter it is restricted only if the person is unable to secure suitable unskilled employment without being employed， depending on individual circumstances. These restrictions can be waived but require approval from both DHS and USCIS before granting permission.