When filing a claim for disability benefits, your alleged onset date (AOD) is the day on which you assert you met the technical and medical requirements for disability benefits. Your alleged onset date helps determine how far back your disability payments will reach. It often coincides with the date you last worked, since the first step in proving your disability claim involves showing that you have not engaged in substantial gainful activity since your alleged onset date.
However, if you did not receive medical treatment around your asserted time frame, it may be difficult to show your medical impairment began on the alleged date. Where precise medical evidence does not date back to the alleged onset date, the adjudicator may reasonably infer the onset of a disabling impairment based on the evidence in the file (SSR 83-20). Going back a few weeks or months prior to treatment may be entirely reasonable, though the individual facts of any particular case will vary.
At times, the evidence may suggest that the onset of disability occurred on a date other than the date alleged. In such instances, the decision-maker may award a partially favorable decision with an established onset date (EOD). An established onset date is a disability date later than the one alleged by the claimant.
Alternately, the claimant may wish to amend his or her onset date after filing. Claimants can amend the alleged onset date by contacting the field office via telephone or letter, or by providing testimony at a hearing (POMS DI 25501.230). However, in no circumstances should Social Security Administration persuade or require the claimant to amend his or her alleged onset date. Claimants should contact their attorney or legal representative to determine whether amending the onset date is the correct action for their claim.