What happens while my application for adjustment of status is pending?

If you have submitted an application for adjustment of status (a green card) to U.S. Citizenship and Immigration Services, then your case will likely be pending for several months while you await the interview at which USCIS makes a decision. During this time, you are considered to be in lawful status, and assuming you included Form I-765 in your adjustment packet, you also have the right to work. (If you didn't submit this form to request a work permit, you can do so now, but will have to pay a separate fee.) 

You also have the right to travel outside the U.S. while you wait, assuming that you applied for "advance parole" (using Form I-131) as part of your adjustment packet. Without having applied for advance parole, leaving the U.S. will result in USCIS cancelling your application, believing you to have abandoned it. But you should NOT leave the U.S. if you could be found inadmissible upon your return. 

Be careful about planning any long trips close to the time your interview date might happen, however. Requesting a rescheduling will naturally cause a delay in your case, and if a miscommunication happens, could result in your case being denied on the grounds that you didn't show up when you were supposed to. To find out how long your local USCIS office is taking to call people in for interviews, see the "USCIS Processing Time" page of its website, and select your field office from the drop-down menu.

During the wait, you will be called in for your "biometrics" appointment, at which your fingerprints will be taken. Then USCIS will send your prints to the FBI for a check of your criminal and immigration record.

At last, you will receive a notice of your interview date and time. Make sure to leave plenty of time for parking and getting through the security line in front. (This is a federal building, and you will have to pass through a metal detector.) For more tips on the interview itself, see "What to Expect in an Adjustment of Status Interview."