VA presumptive chronic diseases: the list and the clock.

The short version

Some diseases take years to show themselves, and a veteran who develops one shortly after leaving service may have no medical record of it from service days. The regulation fills that gap with a presumption. If a disease is on the list in 38 CFR 3.309(a), and it shows up soon enough after the veteran leaves service, VA treats it as having been incurred in or aggravated by service even though there is "no evidence of such disease during the period of service." This page lays out the three ingredients: the length of service, the list, and the clock.

The text is from the eCFR, current as of October 29, 2026. It is a reading aid; whether any specific veteran meets these requirements is for VA to decide.

Ingredient one: 90 days of service

Section 3.307(a)(1) says the veteran must have served 90 days or more during a war period or after December 31, 1946. The regulation calls this "active, continuous service" within or extending into a war period, or one that began before and extended beyond December 31, 1946, or began after that date. There are carve-outs: for the conditions listed in 3.309(c) (former prisoner of war diseases) and 3.309(e) (herbicide diseases), any period of service is enough. The same is true for the Camp Lejeune list in 3.309(f) when the service otherwise qualifies for the Camp Lejeune exposure presumption.

Ingredient two: the 3.309(a) list

The regulation says "No condition other than one listed in § 3.309(a) will be considered chronic" for this purpose. The list, in the order the regulation gives it:

Several entries carry explanatory notes in the regulation itself. "Cardiovascular-renal disease" is said to apply to a combination involvement of arteriosclerosis, nephritis and organic heart disease, and because hypertension is an early symptom long preceding those diseases in their more obvious forms, "a disabling hypertension within the 1-year period will be given the same benefit of service connection as any of the chronic diseases listed." "Endocarditis" is said to cover all forms of valvular heart disease. For peptic ulcers, the regulation says a proper diagnosis is considered established where the preponderance of evidence indicates it, and laboratory findings should be used in corroboration whenever possible.

Ingredient three: the clock

Section 3.307(a)(3) requires that the chronic disease "must have become manifest to a degree of 10 percent or more" within one year from the date of separation. There are two longer clocks: three years for Hansen's disease (leprosy) and tuberculosis, and seven years for multiple sclerosis. The date of separation is defined in 3.307(a)(2): for wartime service, the date of discharge or release during a war period, or, if service continued after the war, the end of the war period; for service on or after January 1, 1947, the date of discharge or release from the period of service on which the claim is based.

Use the checker below to compare a gap in months against these windows. Enter the months from separation to the date the disease first reached 10 percent. It does not decide whether a diagnosis is correct or a condition is rated at 10 percent.

What counts as showing the disease in time

A frequent misunderstanding is that the disease must be diagnosed within the window. The regulation says otherwise. Paragraph (c) of 3.307 states that this "will not be interpreted as requiring that the disease be diagnosed in the presumptive period, but only that there be then shown by acceptable medical or lay evidence characteristic manifestations of the disease to the required degree, followed without unreasonable time lapse by definite diagnosis." Paragraph (b) adds that the factual basis may be established by medical evidence, competent lay evidence or both, and that the diseases in the list will be accepted as chronic even if diagnosed as acute because of insidious inception and chronic development. Exceptions apply where the disease results from intercurrent causes, such as cerebral hemorrhage due to injury, or is the result of drug ingestion or a complication of a condition not related to service.

The regulation also says presumptions cannot be invoked just because the disease had advanced by the time it was first definitely diagnosed. The question is whether characteristic manifestations to the 10 percent level existed in the period.

A worked example

A veteran separates from service in June 2015 after more than 90 days of active service. A listed disease, say Raynaud's disease, first reaches a 10 percent level of manifestation in November 2015, five months later, and is definitely diagnosed in 2016. The clock for a standard chronic disease is one year, so the timing is satisfied: five months is inside twelve. If the same first manifestation had occurred 14 months after separation, the one-year clock would have run, and the presumption would not apply to that disease on those facts. For multiple sclerosis, by contrast, 14 months is inside the seven-year clock.

What can defeat the presumption

Section 3.307(d) allows rebuttal with evidence of a nature usually accepted as competent to indicate the time of existence or inception of disease, including the effect of intercurrent injury or disease. The regulation notes that "affirmative evidence to the contrary" does not require a conclusive showing. The presumption is therefore a starting position, not a guarantee.