Established Onset Date (EOD)

The established onset date is the date the disability applicant first became disabled. Although the claimant will be asked their alleged onset date at the time they apply for SSI or SSDI benefits, the alleged onset date does not become the official or established onset date until it has been verified and approved by a disability adjudicator, SSA examiner, or the disability judge.

Why would my alleged onset date be changed?

Although the onset date is very important and can determine, not only if you qualify for SSDI benefits (i.e., the onset date could be after the date last insured), but also the amount of back pay you may be entitled to receive, there are reasons why the date a claimant alleges to be their onset date and what the SSA considers the actual date could vary.

For example, medical examiners may adjust your onset date if they do not believe your medical records established your disability date as far back as you allege or you performed substantial gainful activity after the date you allege was your onset date.

How do I establish my onset date?

If you have clear medical records which state your diagnosis, prognosis, and your inability to work and you quit working and apply for SSDI benefits immediately, it will be easy to establish your onset date.

If, however, you continue working part-time and wait awhile to apply for disability or you set your onset date months before you apply for SSDI benefits, it will be up to you to substantiate your date of disability or your onset date through medical evidence. You will also have to prove any work you did after your onset date was not gainful or substantial.

Consider, the established onset date and the alleged onset date may be different if the claimant does not have medical information to support the AOD or they performed additional substantial work after their AOD.

(See also alleged onset date)