If the visa you have in your passport is still valid, you can enter the US on that visa and when the employer files an extension on your behalf, you willÂ  not need to get a new visa in your passport if you are in the US; your status will just be extended when the petition is approved.Â  The next time you travel outside the US, however, you would need to get a new H-1B visa that will be tied to the expiration date of the renewal.