One of the oldest presumptions in the VA's regulations has nothing to do with a specific exposure. It applies to any veteran whose listed chronic disease shows up soon after leaving service.
What the rule says
38 CFR 3.307(a)(3) provides that a chronic disease listed in 38 CFR 3.309(a) that becomes manifest to a degree of 10 percent or more within one year of separation from qualifying service is presumed to have been incurred in service.
Some diseases in the regulation carry longer windows - tuberculosis and multiple sclerosis, for example, have their own periods stated in the text.
The chronic disease list
The list in 38 CFR 3.309(a) is long and includes conditions many veterans claim: arthritis, hypertension, diabetes mellitus, organic diseases of the nervous system, endocarditis, nephritis, psychoses, and several cancers among them.
The presumption only reaches the diseases actually named. A condition off that list follows the ordinary route in 38 CFR 3.303.
Why the medical record matters here
This presumption depends entirely on documented timing and severity within that first year. Records from the year after discharge - private treatment, VA care, or a diagnosis date - are what make or break it.
When the timing cannot be documented, the claim falls back to direct service connection, where a medical opinion about the origin of the condition carries more weight. See our guides on how VA service connection works and when a presumptive claim still needs medical evidence.
Where veterans start
Every case is different, and there is no obligation at any step. When veterans want to understand what their records actually support, these are the two most common starting points:
- Medical records review
A licensed physician reviews your records for a $250 flat fee and identifies which conditions the available evidence may support. The fee is refunded in full if nothing supportable is identified.
- Nexus letter
When the records support one, a licensed provider writes the medical opinion that addresses the link between your condition and your service.
How the one-year window is measured
The clock in 38 CFR 3.307(a)(3) starts on the date of separation from the qualifying period of service, not the date symptoms first appeared or the date a veteran first sought treatment. A diagnosis or a documented worsening that lands within that twelve-month window can support the presumption, even if the underlying symptoms began earlier or were not immediately diagnosed.
Because the deadline is fixed, veterans who believe they may have a chronic condition from the list are generally better off documenting it as soon as it appears rather than waiting, since evidence created inside the window - as opposed to a provider's later opinion about when the condition likely began - is usually the more direct way to satisfy the regulation.
Evidence that establishes the 10 percent threshold
It is not enough that a condition existed within the year; the regulation requires that it reached a degree of 10 percent or more under the VA's rating schedule during that period. For a condition like hypertension or diabetes mellitus, this usually means specific clinical findings - blood pressure readings, lab values, or documented treatment - matching the criteria in the rating schedule for that disability at the 10 percent level or higher.
Treatment records, private physician notes, and service department records from the months immediately after discharge are the most direct evidence for this. A general statement that a veteran was unwell after service, without clinical detail, usually is not enough to establish the specific severity level the regulation requires.
When the one-year rule does not apply
If a listed chronic disease first reaches a compensable degree after the one-year window closes, the presumption in 38 CFR 3.307(a)(3) no longer applies, and the claim is decided under ordinary direct service connection principles in 38 CFR 3.303. That does not mean the claim fails - it means the veteran, rather than the regulation, has to show the medical link between the current condition and service, typically through a medical opinion addressing that connection.
This guide is educational. It summarizes the VA's own published rules and links to the exact sources it relies on. It is not legal or claims advice, and it is not a substitute for an accredited representative, who can advise you about your specific claim. Accredited help is free - search the VA's accreditation database to find a Veterans Service Organization, accredited agent, or attorney.
Frequently asked questions
What is the VA one-year presumption?
Under 38 CFR 3.307(a)(3), a chronic disease listed in 38 CFR 3.309(a) that becomes manifest to a degree of 10 percent or more within one year of separation is presumed to have been incurred in service.
Which conditions are on the chronic disease list?
38 CFR 3.309(a) lists dozens of chronic diseases, including arthritis, hypertension, diabetes mellitus, organic diseases of the nervous system, psychoses, and certain cancers.
What does manifest to a degree of 10 percent mean?
It means the condition was severe enough within that year to meet the 10 percent level under the rating schedule - not simply that symptoms existed.