关于旧签证+新I20入境的美国官方Source整理

本人有旧F1签证有效，赴美读master（意味着会拿到新I20，新SevisID，不同学校name）。之前有很多人报了成功入境的帖子。最近在咨询了Yale的International Service的负责人后，整理出一些Citation或许可以支持旧签证+新I20。有些观点是个人观点，欢迎大家讨论！
Note: 入境永远是at the discretion of U.S. Customs and Border Protection。 不过可以打印并携带一下source，以备入关不时之需。

首先，美国国务院(Department of State，以下写成DOS)曾经有以下公告 "DOS on Student Visa Validity Following a Break in Studies"：

"Students who leave the United States for a break in studies of five months or more may lose their F-1 or M-1 status unless their activities overseas are related to their course of study. In advance of travel, students may want to check with their designated school official, if there is a question about whether their activity is related to their course of study."
"When the Customs and Border Protection (CBP) immigration inspector at port of entry is presented a previously used, unexpired F-1 or M-1 visa by a returning student who has been outside the United States and out of student status for more than five months, a CBP immigration inspector may find the student inadmissible for not possessing a valid nonimmigrant visa. CBP may also cancel the visa after granting the student permission to withdraw the application for admission. Therefore, it is prudent for students to apply for new visas at a U.S. Embassy or Consulate abroad prior to traveling to the United States to return to their studies, after an absence of more than five months that is not related to their course of study."

这份公告说明如果离境五个月和失去学生身份五个月，it is "prudent for students to apply for new visas"，但并没有明确说明学生visa会自动失效。不过，DOS告诉学生你有可能会在入境的时候在CBP(Customs and Border Protection)处碰到困难。然而对于这个事情，CBP没有issue官方的指导，因CBP可能会evaluate case-by-case。尽管从以往的经历来看，这个碰到困难的情况是少数(欢迎大家报告新数据点)，但是如果选择不重新签证，要承担这个risk。但是这份公告在2017年被移除。如果相同的公告链接已经导向另外一篇新文章，文章名： SEVP "Questions from DSOs" - Do Students Returning from Temporary Absences Need New Visas? （如果超链接失效，链接放在文末）
而在这篇新文章(on January 26, 2017)中提到尽管学生需要获取新I20和新SEVIS，只需要在visa过期的情况下才需要申请new visa：

"However, if a student has been out of the United States for more than five consecutive months (and not on study abroad), they will need to obtain a new Form I-20, “Certificate of Eligibility for Nonimmigrant Student Status,” and pay the I-901 SEVIS Fee again.  Again, the student would only need to apply for a new visa if their original visa was no longer valid."

但DOS仍然说明UBP才是最终的决定者：

"Please also note that a valid visa does not guarantee entrance into the United States. U.S. Customs and Border Protection agents at the U.S. port of entry ultimately make the decision to admit people into the country, not the Department of State. "

另外一个Source来自DOS的The Foreign Affairs Manual (FAM)：
9 FAM 402.5-5(P)(2)  (U) Temporary Absence of Aliens Applying Abroad for Attendance at School Other than Listed on the Visa
(CT:VISA-1090;   06-24-2020)

(U) A student temporarily abroad who intends to return to study at a United States institution other than the one for which the original visa was issued may seek admission with the original visa, if still valid, and the Form I-20 from the new school.  If the student wishes to apply for a new visa, however, he or she must present proof that the transfer has been effected and the student is in “initial” or “active” status at the new school.  You must verify that the applicant has a valid SEVIS record showing the applicant is in INITIAL or ACTIVE status at the new institution and that the SEVIS fee has been paid on the new record before issuing a new student visa.

附:
DOS公告网址：https://studyinthestates.dhs.gov ... nces-need-new-visas

9 FAM 402.5网址：https://fam.state.gov/fam/09FAM/09FAM040205.html

非常详尽的内容分析，感谢楼主。这样看下来国内大使馆的官方网站以及新加坡/柬埔寨的大使馆相关网站都是按照了2017年之前的公告进行描述的。

楼主我想问一下，如果我申请新的F1被拒了，还能继续用旧的吗（还没过期

同楼上追问，请问申请新的f1被check了，旧签在手可以直接走吗？