I am currently in USA. I have valid visa stamped on my passport till Sep 2016 and also i have approved extension I-797 which has date 13th june 2016 to 30th sep 2018. I want to travel to Germany for some work before sep 2016. My question is as follows:
Do i require stamping before Sep 2016 to enter in US ?
If I enter US without stamping what will be date of my I-94 ? Is it based on new visa approved or old one ?