can son draw off fathers social security if he was diagnosed with disability (bipolar) when he was 15 or possibly collect back money if he did not apply for benefits until after 21 but has papers where he was diagnosed bipolar at age 15

Hi,

It sounds like you're referring to disabled adult child's (DAC) benefits. To qualify for DAC benefits, the DAC's parent needs to either be deceased or drawing Social Security retirement or disability (SSDI) benefits. The DAC must also be unmarried and must have become disabled according to Social Security's standards prior to reaching age 22. If the DAC has performed work that's considered to be substantial gainful activity (SGA) after age 22 and before becoming entitled to DAC benefits, that would normally disqualify them from being able to qualify for DAC benefits.

An application is required in order to qualify for DAC benefits, and benefits can usually be paid for no more than 6 months prior to the month of application. However, if the parent on whose record the DAC is eligible for benefits is receiving SSDI benefits, then up to 12 months of retroactive benefits is possible.

Best, Jerry