尊敬的8老师，
首先非常感谢长期以来你对大家的移民问题的热心解答。
我的朋友，他本人，绿卡等待期，他小孩，H4 签证；小孩大学在读，将很快满21岁，但小孩的H4签证将一直有效到超过21岁， 并且将继续到两年以后， 在那个时候小孩大学已经毕业。 他了解21岁后，小孩将不能跟他继续申请绿卡。
-If the parent has filed I-140, then it is still possible the child may join in the parent's green card application as long as the child CSPA age is < 21.
The child CSPA age = the child actual age when the priority date is current - the I-140 pending time.
Note: I-140 pending time = I-140 approval notice date - I-140 receipt date.
现在的问题是，小孩手中的H4签证：
问题1：本H4签证在小孩21岁后，是否继续有效？
-No. The child's H-4 status automatically expires when the child turns 21 years old. So, the child has to file the change of status (e.g. H-4 to F-1) application before he/she turns 21.
问题2：美国政府在小孩21岁后，会否发通知告知签证问题？
-No. You have to be responsible for your personal status validity.
问题3：如果没有收到任何通知，继续使用本签证，在小孩以后自己申请绿卡时，会有何风险？
-If the child does not change the H-4 status to another status (e.g. F-1) before turning 21, then he/she will be out of status/illegally present when he/she turns 21, and thus he/she will have trouble in the future.
到目前为止， 在个人方面，似乎没有任何错误。
首先非常感谢长期以来你对大家的移民问题的热心解答。
我的朋友，他本人，绿卡等待期，他小孩，H4 签证；小孩大学在读，将很快满21岁，但小孩的H4签证将一直有效到超过21岁， 并且将继续到两年以后， 在那个时候小孩大学已经毕业。 他了解21岁后，小孩将不能跟他继续申请绿卡。
-If the parent has filed I-140, then it is still possible the child may join in the parent's green card application as long as the child CSPA age is < 21.
The child CSPA age = the child actual age when the priority date is current - the I-140 pending time.
Note: I-140 pending time = I-140 approval notice date - I-140 receipt date.
现在的问题是，小孩手中的H4签证：
问题1：本H4签证在小孩21岁后，是否继续有效？
-No. The child's H-4 status automatically expires when the child turns 21 years old. So, the child has to file the change of status (e.g. H-4 to F-1) application before he/she turns 21.
问题2：美国政府在小孩21岁后，会否发通知告知签证问题？
-No. You have to be responsible for your personal status validity.
问题3：如果没有收到任何通知，继续使用本签证，在小孩以后自己申请绿卡时，会有何风险？
-If the child does not change the H-4 status to another status (e.g. F-1) before turning 21, then he/she will be out of status/illegally present when he/she turns 21, and thus he/she will have trouble in the future.
到目前为止， 在个人方面，似乎没有任何错误。
