我持绿卡被派回国内工作，已经两年，办了回美证(permit to re-entry) , 但是每次入境美国都只用绿卡，从来没用过回美证。虽然大部分时间在中国，但回美国很频繁，每两个月左右就回美国一次出差或者探亲，每次在美国一到两个星期。家人孩子房子报税等都还在美国维持正常。
现在的回美证已经两年到期了。预期在中国那边最多再工作五六个月（中间也会频繁回美国的）就回美国了。有点懒得再办回美证延期了。
请教，我这种情况办回美证延期是否有必要呢？谢谢!
-I don't think you need to renew it if you only will work in China for about 6 months. Bring the letter from your employer to prove that you are sent to work in China for the company and also the expired reentry permit, just in case you need to explain it to the IO. BUt you cannot stay in China for > one year continuously.
