What Is Intervening Cause
An intervening cause is an event that occurs after your initial injury or condition and contributes to your disability or inability to work. In Social Security disability claims, the SSA examines whether a later medical event breaks the causal chain between your original condition and your current functional limitations.
This matters because Social Security must establish a clear link between your medical conditions and your inability to perform substantial gainful activity. If the SSA argues an intervening cause severed that connection, they may deny your claim even if your original diagnosis was legitimate.
How Intervening Cause Affects Your Claim
The SSA uses intervening cause analysis primarily when your case involves multiple medical events. For example, if you filed claiming disability from diabetes, but later suffered a car accident that caused new nerve damage, the SSA might argue the accident is an intervening cause that actually explains your current functional limitations, not the original condition.
At ALJ hearings, vocational experts and medical experts frequently debate whether an intervening cause supersedes the original impairment. The ALJ's decision on this point directly affects whether they find you disabled and eligible for benefits. In 2023, approximately 35% of initial SSDI denials involved causation disputes where intervening events played a central role.
The distinction matters for back pay calculations as well. If the SSA acknowledges your original condition but accepts an intervening cause argument, they may establish your disability onset date as the date of the intervening event rather than your initial diagnosis. This can reduce your back pay by months or years.
Medical Evidence Requirements
To overcome an intervening cause argument, you need specific medical documentation showing how your original condition caused your current functional limitations. This means:
- Treatment records that document the progression of your original condition through the claimed disability period
- Medical opinions from your treating providers explaining why the original impairment, not the intervening event, caused your functional limitations
- Lab results, imaging studies, or objective findings demonstrating continuous disability from the original condition
- Detailed functional capacity evaluations addressing your abilities under both your original condition and any intervening condition
Request that your physician provide a written opinion specifically addressing causation. State clearly: "My current functional limitations result from my original [condition], not from [intervening event]." Vague treatment notes will not overcome intervening cause arguments at the ALJ level.
Common Questions
- If I develop a new condition during my SSDI claim, does that automatically become an intervening cause? Not automatically. The SSA must prove the new condition actually broke the causal chain. If both conditions contributed equally to your disability, or if the new condition resulted from your original impairment, the intervening cause argument fails. This distinction is crucial for concurrent causation cases.
- How do I prove my original condition, not an intervening event, caused my disability at an ALJ hearing? Present treatment records with consistent functional limitations attributed to your original diagnosis, obtain a detailed medical opinion from your treating provider addressing causation directly, and ask your attorney to cross-examine the SSA's medical expert about the timeline and progression of your conditions.
- Can an intervening cause argument apply if the original condition already made me unable to work? Generally no. If you were already unable to perform substantial gainful activity due to your original impairment, a later event cannot be the intervening cause of your disability, though it may affect your severity.
Related Concepts
- Proximate Cause - The direct, unbroken connection between your medical condition and your functional limitations
- Concurrent Causation - When multiple conditions jointly cause your disability rather than one superseding the other