How can I find the date of onset?
We recommend using the applicant’s last day of work as their date of onset when helping someone apply for SSI/SSDI. The Social Security Administration (SSA) will examine the applicant’s medical records and prior work history to determine if any of the previous work attempts were unsuccessful (i.e.: the applicant was unable to sustain work for more than a few weeks or months due to disabling mental or physical health conditions).
If the applicant is currently working, enter the date that he or she believes the condition(s) became severe enough to prevent him or her from performing substantial gainful activity.
For individuals who have never worked, such as youth exiting foster care, SSA’s guidance is to “enter the date when he or she believes the condition(s) became severe enough to keep him or her from working.” Since youth can work before age 18, you can enter dates prior to their 18th birthday if that is relevant.