How long i can stay in U.S., after filing H1 B visa Extension?


I have applied for H1B Visa extension in Sept 2017 and got receipt number, its been 5months till today and till now my case status is still in Received and my I94 is expired on October 2017.

How long I can stay in US after the i94 expired?

Is it possible to contact customer service in USCIS regarding the status update?

how long will it take usually to get the H1 B visa extension to get processed?

Thanks in advance

you can stay for 240 days when h1b is pending. You can ask employer to raise service request or upgrade to premium