If your disability claim is denied after a hearing with an administrative law judge, you have the right to request review of that denial by the Social Security Appeals Council. The appeal must be taken within 60 days of the date of the ALJ’s unfavorable decision. You can read more about the Appeals Council review process here.
Writing an Appeals Council request for review is something of an art form. I think the "two minute rule" is the best way to approach your appeal. You should write your request for review so that the person reviewing the appeal can tell in two minutes that the judge made an error, and that the claim should be remanded for a new hearing.
To accomplish this, make pinpoint cites to the ALJ’s decision – give the page, the paragraph and the line number for each alleged error in the decision. Also give a pinpoint cites to the exhibits – by exhibit number, page and paragraph – that demonstrate that the judge erred. And if you are citing to a digital recording of a hearing, you can cite to the hour, minute and second of the statement you want to reference. Accurate, pinpoint citations save a great deal of time for the person reviewing the appeal.
As always, keep your argument short and focused. My requests for review are rarely over three pages.