There are at least four. There is the initial application stage. You have 60 days to appeal after denial. Most people are denied at the initial application. In many states, there is a reconsideration stage. The Commissioner of the Social Security Administration has proposed a second stage not called reconsideration but which essentially performs the same function. Again, after that decision, you will have 60 days in which to appeal. The third stage is the most critical. It is the hearing stage. This is where you meet the Administrative Law Judge. If you are denied at a hearing, you have 60 days to appeal to the Appeals Council, though the Commissioner is trying to abolish that. If you lose at the Appeals Council, you have the right to file in federal court though generally that is extremely difficult and cannot be done realistically without an experienced lawyer.