Since denials and appeals are a common part of the Social Security disability process, many applicants will become acquainted with the Office of Disability Adjudication and Review (ODAR) at some point. ODAR used to be called the Office of Hearings and Appeals (OHA). ODAR offices where hearings are held are still usually referred to as hearings offices (as opposed to regional offices).
ODAR schedules and conducts disablity appeal hearings and employs administrative law judges (ALJs) who make decisions regarding a person's eligibility for benefits after he or she has been denied once or twice (depending on the applicant's state). If the ALJ denies the disability claim again, the applicant can appeal to the Appeals Council, also run by ODAR. ODAR accomplishes this task using two branches: the Office of the Chief Administrative Law Judge and the Office of Appellate Operations.
The ODAR manages the Office of the Chief Administrative Law Judge, which is composed of over 1,000 ALJs across the country. The ALJs conduct de novo hearings (where they take a new look at all the facts) and make a decision regarding entitlement to benefits.
An applicant who's been denied benefits by an ALJ can request that teh claim be reconsidered by the Appeals Council, which is managed by the Office of Appellate Operations. The Appeals Council is not obligated to hear a particular case, and it often sends back cases to the ALJ for another look.