For establishing secondary service connection, is it necessary to prove that the secondary condition was incurred during service?

Establishing secondary service connection does not require proving that the secondary condition was incurred during military service. Instead, the focus is on demonstrating that the secondary condition is the result of, or aggravated by, a service-connected primary condition. This concept recognizes that a veteran's current disability can be linked to another service-connected disability, even if the secondary condition itself did not arise during service.

In claims for secondary service connection, the evidence must show a causal or contributory relationship between the primary service-connected condition and the secondary condition. Therefore, the requirement to prove the secondary condition was incurred during service, as posited in the other answer choices, is unfounded in this context. Instead, the essential aspect is the connection between the primary and secondary conditions, rather than the timing of the onset of the secondary disability relative to the veteran's service.