First you must meet the SSA’s financial requirement:
You must have worked long enough, recently enough, and not made over a predetermined level of income.
Second you must meet the medical requirements:
Social Security lists PTSD as an impairment under Section 12.15 Trauma and stressor-related disorders.
To qualify for disability benefits under this listing, you must present medical evidence of ALL of the following:
Exposure to actual or threatened death, serious injury, or violence;
Involuntary re-experiencing the traumatic event;
Avoidance of external reminders of the event;
Disturbance in mood and behavior, and
Increased arousal and reactivity.
You must also show “extreme” limitation of one, or “marked” limitation of two of the following areas of mental functioning.
Understanding, remembering, or using information; for example, learning new tasks;
Being able to interact with others in a socially acceptable manner;
Being able to focus on tasks and complete them in a reasonable time;
Adapting and managing oneself;
Social Security will want to see that you have a medically documented history of PTSD over a period of at least 2 years