Education

Evidence categories by theory of service connection.

Public VA practice commonly discusses three main theories. This page names typical evidence categories for each. It does not decide which theory applies or whether a claim should be granted.

Direct

A condition began in service or was caused by an in-service event, injury, or disease.

In-service treatment or complaint records
Separation exam notes
Current diagnosis
Clinician opinion linking the current condition to service (when onset was not documented in service)

Secondary

A later condition is claimed because a condition already service-connected caused or aggravated it.

Decision or code sheet for the already service-connected condition
Current diagnosis of the later condition
Clinician opinion on cause or aggravation
Dates showing sequence

Presumptive

Public law or regulation lists places, dates, or exposures that VA treats as associated with certain conditions. A listing is not a decision that a particular veteran qualifies.

Proof of service location and dates that match a public list
Current diagnosis of a listed condition
Medical records documenting that diagnosis

These are public categories only. This website does not choose a theory, write a nexus opinion, or file a claim. Take any checklist to an accredited representative.

Try a condition checklist More explainers