What happens to old H1B after H1B Amendment Approval - I94 validity

Hi @Anil_Gupta,

What will happen to the existing H1B (I797/I94 ) validity once after H1B amendment is approved , lets say existing H1B is valid till Sep 2021, and H1B amendment is approved till Sep 2020.

then If I go back to the previous client/MSA then can I use the previous H1B ? or as soon as amendment is approved , will the existing H1B (2021) becomes invalid ?

Thanks.

The old H1B remains valid as per its validity even after your H1B amendment is approved.

If Amendment Approval is shorter than the old H1B, you can go back to work as per the old H1B client and location.