If you are an immigrant who has applied for a green card from within the United States, by filling out Form I-485 along with other forms and documents, you are using a process called adjustment of status.
With any luck, all will go smoothly: U.S. Citizenship and Immigration Services (USCIS) will accept your mailed-in application as complete (instead of returning it to you with a "request for evidence," meaning further documents or information), will schedule you for a biometrics appointment where your fingerprints will be taken, and you'll attend an interview at which USCIS approves your U.S. permanent residence (green card).
However, it doesn't always work this way. Sometimes, even after asking for post-interview follow-up documents, USCIS denies an adjustment of status application. If that happens, you'll need to look into urgent issues such as:
We'll discuss all those possibilities here.
If USCIS rejects your application for adjustment of status, and you don't have a valid, unexpired right to be in the United States (most likely under a visa), USCIS will send you into immigration court (removal) proceedings. There, you will have the "opportunity" to have an immigration judge hear your case.
The good news is, that's not the worst thing that could happen. Unless something emerged in the USCIS review that make clear you're ineligible for the type of green card you were seeking (or if USCIS revoked the petition on which basis you were applying, such as an I-130), the immigration judge can take another look at whether you qualify.
In many cases, USCIS denials are for sufficiently serious reasons that renewal won't be possible, or the judge won't likely be convinced. But USCIS does make mistakes, so this avenue could work.
After rejecting your application for adjustment of status, USCIS will send you a written notification informing you of the reason for the denial. There is no procedure for appealing this decision.
But you might be able to request that USCIS review its decision. Or you could simply apply all over again, as described below.
In certain situations, you can ask USCIS's Administrative Appeals Office (AAO) to review the decision. This is done on USCIS Form I-290B. However, you'll need an attorney's help with this. The idea is to prove that the USCIS personnel who reviewed your case made a mistake, and USCIS rarely likes to admit to mistakes. You must pay an application fee for this review, which was $675 in late 2021.
It is important to file a request for review quickly. You have 30 calendar days from the date of service of the decision to submit the request. If the decision was mailed to you, you must submit the request within 33 calendar days. Weekends and public holidays are counted while determining the number of days. Once USCIS receives your request to review, it will process your request and inform you of its decision in writing.
Most adjustment of status denials are made "without prejudice," meaning you can file another application for a green card. This can actually be easier than filing a request for review, because you're not asking USCIS to admit a mistake.
However, if you don't have a lawful right to remain in the United States, you might have to leave and either return or do the bulk of the application process through a U.S. consulate. Meanwhile, if you've already spent time in the U.S. unlawfully, you might not be allowed back in for several years. (That's because you will likely have become inadmissible due to your record of unlawful presence in the United States.)
Don't make a decision about what to do without consulting an attorney first.
Of course, you'll need to make sure that you've cleared up whatever underlying problem caused your adjustment of status application to be denied in the first place. Unfortunately, not all problems can be cleared up. For example, if you're clearly inadmissible because of a criminal record, or USCIS has obtained convincing evidence that your marriage is fraudulent (and it really is), neither appeals nor further applications are likely to help much.
Adjustment of status is granted at the discretion of USCIS. If your application for adjustment of status has been denied, you can be subject to deportation (removal) proceedings. Seek the assistance of an experienced U.S. immigration attorney. The attorney can help you decide what to do next.