Even if you have an employment authorization document (EAD) for work purposes and an advance parole document (AP) for travel purposes, extending your H-1B visa while your green card application is pending might be worthwhile depending upon your circumstances. Here are three reasons why an H-1B extension could make sense for you:
Safety – if your I-485 application is denied for any reason (even government mistakes), you will have no legal status and can be deported unless you have have nonimmigrant status like H-1B. Also, if you have H-1B status, you may be eligible to re-file your I-485 application. Without it, you might not.
Automatic Extension – even if you file your H-1B extension request the day before your H-1B expires, you will remain in H-1B status and continue to work without interruption while your extension request is pending. This is not true with the EAD. If your EAD renewal is not approved before your current EAD expires, you are not authorized to work until your EAD renewal is approved. Also, you have a small window of time to file the EAD renewal. To be safe, you must file 90 to 120 days before your EAD expires (you cannot file earlier than 120 days before expiration).
Family – if your spouse or child did not file or cannot file for adjustment yet, then maintaining H-1B status may be necessary to maintain status for your dependent spouse or child. Also, if you marry or plan to marry someone who needs a visa, the H-4 visa based upon your H-1B status is the fastest way for him or her to join you in the U.S.
There are many factors to consider in determining the best immigration status for you while your green card application is pending. Even if you decide not to extend your H-1B status or you travel using AP rather than an H-1B visa, you may still have an option of reinstating your H-1B status if necessary. Always consult with an immigration attorney when considering any changes to your immigration status.