Here is some guidance on what to bring to that interview. You will also receive a list from USCIS, so read it carefully and include anything on that list that you don't see mentioned below.

Photo Identification and Passport

You and your spouse will each need to present photo identification. Your passport is best. If you don’t have a passport, use a separate form of photo identification for the interview. The U.S. citizen or permanent resident spouse usually presents a driver’s license.

Original Documents and All Work or Travel Permits

Assemble the originals of the documents you used to enter the United States, and any other documents you’ve received from U.S. consulates or USCIS (or the formerly named INA) offices, such as an Advance Parole travel permit or a work permit, also called an Employment Authorization Document or EAD.

Also, if you’ve mailed copies of documents to USCIS, such as your marriage and birth certificates, bring the originals.

Your spouse will need to bring the original proof of U.S. citizenship status (a birth certificate, naturalization certificate, or passport) or permanent resident status (a green card or stamp in his or her passport).

The USCIS officer may not ask for all of these, but you’ll be glad you brought them if the officer does ask. Also realize that the officer may keep the EAD, since it's no longer valid. Your green card will serve as your proof of right to work in the United States. It will not arrive for a few weeks, however, so if you need such proof in the meantime, ask for an approval letter or an I-551 stamp in your passport.

Updates to Materials in the Application

Has anything important in your life changed since filing the adjustment of status paperwork? If, for example, you or your spouse have a new or different job, bring a letter from the new employer and copies of recent pay stubs. (Of course, your spouse’s income still needs to be high enough to deal with the affidavit of support requirements. If it has gone down, you, the immigrant, may be able to help by bringing proof that you are now working in the United States.)

If you and your spouse have reached the two-year anniversary of your marriage since filing the application, be ready to remind the officer of this, so you’ll be approved for permanent, not conditional, residency. If a tax year has passed, bring a copy of your latest tax returns (or better yet, an IRS transcript of these returns).

And even if nothing has changed, prove that fact with a recent pay stub showing that the financial sponsor is still bringing in the income.

Required Documentation That You Haven’t Already Sent

During the course of your application process, USCIS may tell you it’s okay if you haven’t sent a necessary document yet because you can just bring it to the interview. For example, if you haven't already turned in the Form I-693 immigration medical examination signed by the doctor, now is the time to do so. This will be inside a sealed envelope you got from the doctor.

Proof That Your Marriage Is Real

The interview is the most important opportunity for the USCIS officer to decide whether your marriage is “for real.” The documents you show are important factors in this decision. They should show that you and your spouse’s lives are intertwined and that you trust each other with your financial and personal matters.

Below is a list of documents most immigrants present. However, this list isn’t engraved in stone. Use your imagination and be ready to do some organized “show-and-tell.” No need to flood the officer with paper—copies of six items from this list would be a reasonable amount.

• rental agreements, leases, or mortgages showing that you live together and/or have leased or bought property in both spouses’ names
• your mutual child’s birth certificate or a doctor’s report saying that one of you is pregnant
• utility bills in both your names
• joint bank statements
• joint credit card statements
• evidence that one spouse has made the other a beneficiary on his/her life or health insurance or retirement account
• auto registrations showing joint ownership and/or addresses
• joint club memberships
• receipts from gifts you purchased for one another (such as jewelry, flowers, or candy)
• emails, texts, or letters between you and your spouse, and letters from friends and family to each or both of you mailed to your joint address
• proof of having named the other spouse as the beneficiary of a will (for a cost-effective, highly regarded means of preparing one, see Nolo's online will)
• signed, sworn affidavits from friends or family who have observed the progress of your relationship and your wedding, and share their knowledge in detail
• photos of you and your spouse taken before and during your marriage, including photos from the wedding. (USCIS knows wedding pictures can be faked, but many officers enjoy seeing them anyway.) The photos should, if possible, include parents and other relatives from both families. And you should be fully clothed in your photos—USCIS doesn't want to see intimate photos. Write the date taken and a brief description of what the photo shows on the back (or underneath, if photocopying them). Don’t bother with videos of the wedding or other events—there won’t be time or a space to view them.