Should I file to renew my permanent resident card if I have a pending N-400 naturalization application?
Yes, if your card will expire within six months of filing an N-400. No, if you file Form N-400 while your card is valid for at least 6 months. You must be eligible to file Form N-400 at the time you file, regardless of the expiration date of your “green card.”
If you file according to the above timelines, you will be able to obtain proof of your status—a stamp in your passport called “Alien Documentary Identification and Telecommunication” (ADIT) stamp as temporary proof of permanent residence.