If you missed the deadline for filing the appeal in your Social Security claim you may be able to ask Social Security to accept the late appeal. You must have a “good cause” for filing late. In other words, you need a good reason that you did not file the appeal on time.
You must have a really good reason for asking to file a late appeal. Examples of good cause are death or serious illness in your immediate family or that you did not receive the decision. You will likely need to provide proof, such as a death certificate. If your mental illness or lack of understanding of the English language caused you to miss the appeal date, that may also be enough for Social Security to extend the deadline. There are many other good reasons why you might have missed the filing deadline.
If your request for a good cause exception is not accepted, the date you filed the request should be treated as the filing date for a new claim.