Summary: Secondary service connection may allow VA to compensate a condition caused or aggravated by an existing service-connected disability. Establishing a current disability, an existing service-connected condition, and the medical relationship between them is central to a secondary service connection claim.
A veteran may receive VA disability benefits for a condition that began during military service, but direct service connection is not the only path to benefits. The Department of Veterans Affairs (VA) also recognizes secondary service connection when a current disability is caused or aggravated by a condition that VA has already determined to be service-connected. In other words, a secondary VA disability claim focuses on the medical relationship between an existing service-connected disability and another condition.
A service-connected condition can have health consequences beyond the original diagnosis. For example, VA may consider a knee injury that changes a veteran’s gait and contributes to hip arthritis, or service-connected hypertension that contributes to heart disease, as potential secondary conditions. The fact that a secondary condition developed after military service does not by itself prevent a veteran from seeking secondary service connection. The key issue is whether the evidence establishes the required relationship between the service-connected condition and the additional disability.
Understanding Secondary Service Connection for VA Disability
For veterans seeking secondary service connection for VA disability, the central issue is generally the medical relationship between the current disability and an existing service-connected condition. A secondary claim generally involves evidence of a current physical or mental disability, an already service-connected disability, and evidence linking the two conditions. That connection may involve either causation, where the service-connected condition caused the additional disability, or aggravation, where the service-connected condition worsened another disability.
The connection between the two conditions is often described as a medical nexus. Evidence supporting a secondary VA claim may include treatment records, diagnostic testing, medical records documenting the progression of a condition, or a medical opinion from a qualified provider. Some claims may also include a nexus letter or independent medical opinion (IMO) addressing whether the service-connected disability caused or aggravated the additional condition. No single document guarantees approval, and the evidence must be considered in the context of the veteran’s individual claim.
Eric Gang is a veterans disability attorney and founder of Gang & Associates, a law firm focused on helping veterans pursue the VA disability benefits available to them. Gang represents veterans nationwide in VA disability claims and appeals, including matters before the Board of Veterans’ Appeals and the U.S. Court of Appeals for Veterans Claims. His experience includes complex claims involving PTSD, traumatic brain injury (TBI), toxic exposure, and secondary service-connected disabilities.
Gang notes that secondary conditions can be overlooked when veterans focus primarily on establishing the original service-connected disability. A later diagnosis may appear unrelated to military service even when medical evidence indicates that an existing service-connected condition caused or aggravated it. This can arise in physical health claims, mental health claims, or situations where treatment for one service-connected condition contributes to another medical problem.
Why a Secondary Condition Can Affect Compensation
If VA grants service connection for an additional condition, it assigns a disability rating based on severity. VA then uses its combined-rating method when a veteran has multiple ratings. The percentages are not simply added together, so a new secondary rating does not automatically produce a particular combined rating or payment. It may, however, affect the veteran’s overall VA disability rating and disability compensation.
Secondary service connection should also be distinguished from other routes to veterans benefits. A veteran may have a direct service-connected disability, an increased-rating claim, a presumptive claim involving the PACT Act, burn pit exposure, Agent Orange, or certain Gulf War illnesses, or a claim for Total Disability based on Individual Unemployability (TDIU). PTSD VA claims, traumatic brain injury (TBI), and claims involving Military Sexual Trauma (MST) can likewise involve different evidence and legal theories depending on the facts.
Evidence and Timing Still Matter
A denied VA claim does not necessarily end the matter. VA’s current decision-review system includes a Supplemental Claim for new and relevant evidence, a Higher-Level Review when the veteran is asking VA to reconsider the existing record, and a Board of Veterans’ Appeals (BVA) appeal. After certain Board decisions, further review may also involve the U.S. Court of Appeals for Veterans Claims (CAVC).
Timing can matter as well because the effective date helps determine when awarded VA disability benefits begin and may affect VA back pay. For veterans considering a new secondary claim or VA disability appeal, the practical first step is often to identify the diagnosed condition, the existing service-connected condition, and the evidence that connects them.
The broader point is that a veteran’s VA disability claim may involve more than the original service-connected condition. Secondary service connection provides a potential path for VA to evaluate an additional disability when evidence shows that an existing service-connected condition caused or aggravated it. Because secondary service connection is not automatic, the medical evidence establishing the relationship between the conditions remains central to the claim.
