If you became a U.S. conditional resident based on marriage to a U.S. citizen, and you filed Form I-751 (to remove the conditional nature of your permanent residence) with U.S. Citizenship and Immigration Services (USCIS) during the 90-day period before your status would expire, you may find that USCIS doesn't answer your petition before your green card does, in fact, expire.
What then? This is where your receipt notice from USCIS becomes important.
Once the USCIS Service Center has received your application is and reviewed it to see that you have included all the appropriate documents and fee, you will get a receipt notice on USCIS Form I-797. Several weeks may pass before you get this receipt notice.
The I-797 receipt notice is an important document. It extends your residency for a period designated by USCIS (normally 12 months). The notice will be your only proof of your legal status after you green card has expired. The notice is a bit awkward to show to employers, border patrol officers, and others, but it really is an official document. You must, however, also carry your expired green card with you at the same time. That's because your card, unlike the receipt, has your photo on it.
You will, during this time period, be sent an appointment notice stating when and where you must appear for biometric processing. This is usually done at a USCIS Application Support Center (ASC). Biometric processing includes taking your photograph, signature, and index fingerprint, for use in generating your new green card. If you are between ages 14 and 79, it also includes taking your fingerprints, in order to do another criminal background check.
Most people receive their permanent resident cards before the expiration of their extension on Form I-797. If you fall into the group of people who do not get their cards in a timely manner, do not worry that this will affect your legal status in the United States. You will remain a conditional resident until USCIS makes a decision on your application.
If, however, you need evidence of your legal status during this limbo period, visit your local USCIS office, and bring a current, valid passport. You should make an INFOPASS appointment through the USCIS website first. USCIS will give you what’s called an I-551 stamp in your passport, which will serve as evidence of your status. This stamp will not expire for another year. If you request it, the information officer will also send an inquiry to the Service Center handling your case, pointing out that your case has gone beyond normal processing time.
With any luck, the USCIS Service Center will approve your permanent residence by mail before long. Or, it may call you and your spouse in for an interview first.
If it's getting close to the time when you can apply for U.S. citizenship and USCIS still has not given you a decision on your I-751, you don't have to wait to apply for citizenship. Although USCIS cannot actually give you citizenship unless the I-751 is approved, if it sees that you still have an I-751 pending when you apply, it will take care of your I-751 first, then process your citizenship application.
Do not travel with an expired receipt notice! If you do not get your permanent resident card by the time your receipt notice expires, make an INFOPASS appointment and get a temporary stamp in your passport before you leave the United States. If you fail to do so, you may not be let back in.