Service connection and in-service aggravation

V.ii.2.A.1.a · Start with the three required elements

Direct service connection requires a current disability, a disease/injury/event in service, and a relationship between them. Review all relevant medical and lay evidence, including the places, types, and circumstances of service. A service event alone is not the whole claim.

The relationship may be established through the listed-chronic-disease rules in 3.303(b), or through the medical nexus and continuous-symptom evidence described in 3.303(a). Apply the evidence and reasonable-doubt rules linked in the original block.

V.ii.2.A.1.b · A disability can count even if it later resolves

A disability present when the claim was filed or while it was pending satisfies the current-disability element even if it resolves before the decision. A diagnosis near the claim date—approximately within the preceding year—can also establish this element after case-specific review. This is an evidence review, not an automatic one-year exclusion rule.

Distinguish three situations. A clear valid diagnosis that later resolves can support a grant, generally with staged evaluations, when the other requirements are met. An earlier treating or unconfirmed diagnosis that is now absent but has not been reconciled needs a medical opinion about whether it was valid. A reasoned finding that the earlier diagnosis was erroneous supports denial when no other medical evidence refutes it.

The manual contrasts well-established recurring eczema with a later examination finding no active pathology, and claimed sinusitis where the medical evidence instead establishes a traumatic deviated septum and explains why sinusitis was not actually present. Preserve the supported alternative condition rather than treating every earlier label as a confirmed diagnosis.

V.ii.2.A.1.c · An adequate direct nexus does not need a redundant opinion

Under 3.303(a), medical evidence or an opinion can establish the relationship to service. Competent medical evidence of continuous symptoms can also establish that relationship, including for conditions that are not on the 3.309(a) chronic-disease list. When nexus is already established, another nexus opinion is unnecessary.

Here continuous symptoms means symptoms continuing or regularly recurring with minimal interruption from service. Isolated symptoms that do not establish that relationship may call for a medical opinion when the examination threshold is met.

V.ii.2.A.1.d · Use the special chronicity rule only for listed diseases

The chronicity and continuity route in 3.303(b) applies to diseases listed in 3.309(a). When this rule establishes nexus, an additional nexus opinion is unnecessary. A condition being medically chronic is not by itself proof that it belongs to that regulatory list.

V.ii.2.A.1.e · Identify real chronic disease in service

For a listed chronic disease established in service, later manifestations of that same disease are service connected unless an intercurrent cause explains them. The in-service evidence must identify the disease and establish chronic disability; isolated findings or the word chronic in a diagnosis are insufficient.

The manual’s example is arthritis confirmed by X-ray during service, claimed years later, with no intervening injury. Silent later treatment records do not create a need for a nexus opinion when onset and chronicity are already established. If chronicity is legitimately uncertain, examine continuity. Nonlisted diseases use the 3.303(a) nexus route.

V.ii.2.A.1.f · Use continuity when listed-disease chronicity is uncertain

Continuity of symptomatology can establish the relationship for a 3.309(a) disease when the condition noted in service was not clearly chronic or its chronicity may legitimately be questioned. This particular 3.303(b) route is limited to the listed diseases; it does not erase other ways to establish a direct nexus.

V.ii.2.A.1.g · A diagnosis after discharge can still be related to service

Under 3.303(d), consider direct service connection even when the disease was first diagnosed after discharge. Review all evidence on whether it was incurred in service rather than treating the later diagnosis date as an automatic bar.

V.ii.2.A.1.h · Do not make your own medical finding that an injury was temporary

An acute condition is short-lived, has identifiable symptoms, and resolves without apparent residuals. A transitory condition is not permanent. The manual gives colds, pneumonia, bruises, and certain seasonal or allergen-triggered reactions as examples.

Do not independently label a service injury acute and transitory without competent medical evidence addressing chronic disability. Allergic conditions require the whole evidentiary showing under 3.380, although seasonal or acute manifestations resolving after the allergen is removed are generally acute.

V.ii.2.A.2.a · Check the actual entrance examination

Soundness generally means the claimant was sound when examined, accepted, and enrolled, except for a condition actually noted at entry or rebuttal by clear and unmistakable evidence of both preexistence and no aggravation. A reported history alone is not a notation.

An examination must have occurred, but its report need not still be available: a lost report does not defeat soundness. An entry finding must meet the applicable definition of disability. Abnormal hearing below the VA hearing-loss criteria in 3.385 does not itself establish a noted hearing-loss disability.

V.ii.2.A.2.b · Check the service period’s soundness requirements

Peacetime service before January 1, 1947 requires six months or more of active continuous service under 3.305(b). Wartime service and peacetime service from January 1, 1947 have no minimum-service requirement for this presumption under 3.304(b). The separate entrance-examination and other applicability requirements still matter.

V.ii.2.A.2.c · VA must establish both facts to rebut soundness

When the condition was not noted and soundness applies, rebuttal requires undebatable evidence that the disease or injury manifesting in service both existed beforehand and was not aggravated. Preexistence alone is insufficient.

Personality disorders are not diseases or injuries for this presumption. Even when soundness applies, service connection still requires a nexus between current disability and the service disease or injury.

V.ii.2.A.2.d · Evaluate breaks in continuous service case by case

An extended unauthorized absence or other extended non-pay period can interrupt active continuous service, but every absence does not automatically do so. Examine its nature, length, circumstances, and effect on continuous duty.

The original contrasts an absence lasting 1,344 days followed by only nine days of duty, which did not meet the relevant continuity requirement, with a 13-day absence followed by a voluntary return that did not break continuity for the cited presumption. These examples illustrate case-specific analysis rather than a new fixed absence cutoff.

V.ii.2.A.2.e · ADT soundness has additional prerequisites

For an ADT-based claim, apply soundness only when there was an examination at entry into the actual ADT period and previously established Veteran status from prior active military service discharged under conditions other than dishonorable. Prior Veteran status does not replace the examination requirement.

Read the linked aggravation article separately for the Hill exception when service connection for one disability establishes active service and Veteran status for the same training period. That exception is different from assuming all training periods carry the active-duty presumptions.

V.ii.2.A.2.f · Verify what makes an IADT period qualifying service

IADT does not count as active service merely because training occurred. The rule covers disability from a qualifying injury, and the specified acute myocardial infarction, cardiac arrest, or cerebrovascular accident during IADT, including the applicable direct-travel provisions. Ordinary disease alone is not the same as a qualifying injury or listed event.

The manual recognizes disabling injury from an anthrax or COVID-19 vaccine during IADT and PTSD resulting from MST during IADT as potential qualifying injuries. Check the actual period, event, direct travel where applicable, and linked rules.

V.ii.2.A.3.a · Verify when and under what circumstances an injury occurred

Development and rating must review STRs and personnel evidence to establish that the injury occurred during service and in line of duty. A current wound residual could instead come from an injury before or after service. Follow the linked misconduct and line-of-duty rules when raised.

V.ii.2.A.3.b · Describe an uncertain scar without inventing its cause

A scar can have existed at entry, arisen during service, or resulted from a later injury. If its origin is uncertain, describe it without calling it a gunshot or shrapnel residual unless the evidence supports that description.

V.ii.2.A.3.c · Connect a claimed scar to the actual service evidence

When an examination identifies a scar in a scarring claim, review official records to determine whether it resulted from a service wound. If the evidence is in approximate balance on that relationship, apply reasonable doubt and award service connection as the manual directs. Review the linked scope rule for scars reasonably included in another claimed issue.

V.ii.2.A.3.d · Combat evidence can establish occurrence without an official record

Accept satisfactory lay or other evidence consistent with the circumstances, conditions, or hardships of combat when clear and convincing contrary evidence does not refute it. Missing official documentation alone does not defeat that supported combat occurrence.

This lightens proof of the service disease, injury, or aggravation. It does not dispense with current disability and nexus. Follow the linked rules for establishing combat participation and weighing the evidence.

V.ii.2.A.3.e · Assess credibility from the evidence

Satisfactory evidence generally means credible evidence. Consider internal consistency and plausibility, and assess contradictions with other evidence using the manual’s credibility and weighing rules. Explain the evidence finding rather than using an unsupported credibility label.

V.ii.2.C.1.a · Choose the correct legal starting point

A condition actually noted at entry uses the aggravation framework in 38 U.S.C. 1153. A condition not noted, but later alleged or shown to preexist service, requires the soundness analysis under 1111 when that presumption applies. The two situations place different burdens on VA and the claimant.

V.ii.2.C.1.b · Use supported evidence to establish preexistence

When soundness applies, only clear and unmistakable evidence establishes preexistence. Carefully weigh medical records from before, during, and after service and credible lay history. Do not rely on speculation; the medical analysis must account for the history, data, and accepted understanding of the condition’s nature and course.

V.ii.2.C.1.c · An MEB or PEB conclusion needs an explanation

Give service Medical Evaluation Board and Physical Evaluation Board reports their proper evidentiary weight. A bare conclusion that a condition preexisted service and was not aggravated, without supporting analysis, is not enough by itself to rebut soundness or deny the claim.

V.ii.2.C.1.d · Apply the rules for history and statements against interest

There is no absolute requirement for contemporaneous pre-service clinical records. A later medical opinion based on the Veteran’s history may establish preexistence if it meets the clear-and-unmistakable standard after all probative evidence is weighed.

A signed in-service statement against the claimant’s interest about onset cannot be used without other evidence establishing preexistence under 3.304(b)(3); consider the remaining evidence as if that restricted statement did not exist. Other voluntary admissions may be considered with appropriate credibility and weight.

V.ii.2.C.2.a · Where soundness applies, VA must rebut both preexistence and aggravation

VA needs clear and unmistakable evidence both that the disability preexisted service and that service did not aggravate it. The latter means undebatable evidence of no increase, or that an increase was due to natural progression.

Review the entire record. Absence of a documented injury, pre-service records, or post-service treatment does not alone answer the medical course or shift the burden to the Veteran. Its relevance depends on supported medical analysis.

V.ii.2.C.2.b · For a noted condition, first determine whether it worsened

For a preexisting condition noted at entry into active service, the claimant first establishes an increase in disability during service. Once that increase is proven, presume aggravation unless clear and unmistakable evidence shows it was due to natural progression.

Always address aggravation when claimed. A decision declining service connection must explain the relevant evidence before, during, and after service and why it establishes no increase or natural progression. Use independent medical evidence, not speculation.

V.ii.2.C.2.c · Training-period aggravation differs, with a same-period exception

Ordinarily, ADT or IADT aggravation requires direct evidence of permanent worsening during the qualifying training period beyond natural progression; the usual presumption does not automatically apply.

Under the Hill exception, if a grant for another disability establishes Veteran status and active service for the same ADT/IADT period, the presumption of aggravation applies to another preexisting disability when an entrance examination or other contemporaneous evidence establishes its baseline. A grant relating to a different period does not by itself establish this exception.

V.ii.2.C.2.d · Keep the two burdens separate

No disability noted at entry with applicable soundness: VA must clearly and unmistakably establish both preexistence and no aggravation. Disability noted at entry: a supported increase triggers aggravation unless clearly and unmistakably due to natural progression. Do not require the claimant to prove aggravation under the first situation’s unrebutted soundness presumption.

V.ii.2.C.2.e · Temporary symptoms are not always underlying worsening

Under the ordinary preexisting-condition rule, temporary or intermittent flare-ups are insufficient unless the underlying condition worsened. A condition being in remission at entry and symptomatic later is not by itself proof of aggravation. Apply the special combat/POW rules separately when relevant.

V.ii.2.C.2.f · Separate ordinary treatment effects from other aggravation

The usual effects of treatment intended to correct or improve a preexisting condition—such as ordinary postoperative scars or absent/poorly functioning parts—are not service connected unless the disease or injury was otherwise aggravated by service. Review actual medical findings about the underlying condition and residuals.

V.ii.2.C.2.g · A chronic-disease presumption can establish aggravation

The Splane rule permits presumptive aggravation when a preexisting chronic disease first reaches a degree of at least 10 percent within the applicable post-service presumptive period. Verify the disease, service, time, and degree requirements. Affirmative contrary evidence or an intercurrent post-service disease/injury can rebut it under 3.307.

V.ii.2.C.2.h · Apply the special combat and POW aggravation rules

For combat, accept satisfactory evidence of aggravation consistent with service circumstances despite missing official records, unless clear and convincing evidence refutes it. Current disability and competent nexus evidence remain required.

Under 3.306(b)(2), symptomatic manifestations during or proximately after enemy action or former-POW captivity trigger the aggravation presumption unless clear and convincing evidence establishes no increase or natural progression. Do not apply the ordinary flare-up rule without considering this exception.

V.ii.2.C.2.i · Review the entire medical history in combat cases

When assessing rebuttal, consider all relevant factors, including record availability, the nature and course of the disability, elapsed time, and periods without complaint. Missing treatment records do not necessarily mean the disability was absent, particularly in combat. Explain how the evidence bears on the actual condition rather than equating silence with no disability.

V.ii.2.C.3.a · Look beyond entrance records for the baseline

The baseline review draws on all medical records for the condition. It is not restricted to the enlistment and entry-on-duty records. Obtain and consider relevant evidence before deciding what severity was present at entrance.

V.ii.2.C.3.b · Deduct only an ascertainable entrance evaluation, with a total-evaluation exception

After in-service aggravation under 1153 is established, deduct the supported entrance evaluation from the present evaluation when the entrance percentage is ascertainable. If it is not ascertainable, do not deduct it. Do not make a baseline deduction when the disability has a total 100-percent evaluation under 4.22.

These are in-service aggravation rules. Secondary aggravation under 3.310 has different baseline and total-evaluation instructions; use the actual legal basis.

V.ii.2.C.3.c · Real aggravation can result in a zero-percent evaluation

Actual increased severity can establish aggravation even when current and baseline severities fall within the same schedular percentage. In that situation, grant service connection and assign a noncompensable evaluation. The disability need not cross a rating-percentage threshold to have worsened. The no-deduction exception for a total evaluation still applies.

V.ii.2.E.1.a · A defect is generally static

A congenital or developmental defect is a normally static structural or inherent abnormality, usually present from birth and generally incapable of improvement or deterioration. Examples include certain fused vertebrae, an atrial septal defect, pectus excavatum, mental deficiency, and undescended testicles.

Soundness does not apply to such a defect because it is not a disease or injury within the relevant statutes. Still review whether a superimposed service disease or injury caused additional disability under the later block.

V.ii.2.E.1.b · A hereditary disease can change over time

A congenital, developmental, or hereditary disease can improve or deteriorate and may first appear in adulthood. The manual gives polycystic kidney disease, sickle cell disease, retinitis pigmentosa, and Huntington’s chorea as examples. Follow the linked disease-specific rules where applicable.

V.ii.2.E.1.c · Heredity does not automatically prevent service connection

Congenital defects, refractive error, personality disorders, and mental deficiency are ordinarily not compensable diseases or injuries under 3.303(c). But a congenital or hereditary disease can qualify if it first manifests during service, progresses abnormally during service when preexisting, or meets the listed-chronic-disease presumption after discharge. Additional disability caused by an overlying disease or injury to a congenital defect can also qualify.

A degenerative condition is not a congenital defect. Genetic predisposition alone cannot rebut soundness or the chronic-disease presumption, sever service connection, or reduce a disability evaluation.

The original explains that historical retinitis pigmentosa guidance did not prohibit in-service aggravation grants; the subsequent opinions and manual changes were therefore not liberalizing changes. Keep that distinction in any effective-date review and follow the linked eye, severance, presumption, and abnormal-laboratory-finding rules.

V.ii.2.E.1.d · Ask a medical question that distinguishes defect from disease

When the classification is unclear and medical input is needed, ask whether the condition can improve or deteriorate. The opinion helps decide whether it is a disease process or a static abnormality. Weigh the opinion with the rest of the record; it is probative, but not the sole legal determination.

V.ii.2.E.1.e · Use actual manifestation rather than inherited risk as onset

An inherited likelihood of eventually developing a disease is not the disease itself. Actual signs or symptoms of pathology followed by a diagnosis establish manifestation, using case-specific medical evidence and sound medical judgment. A hereditary disease can be incurred in service when those manifestations begin after entry.

Apply soundness when its entrance and service requirements are met. A clear entry examination cannot be overcome merely by heredity; rebuttal still requires clear and unmistakable evidence of both preexistence and no aggravation.

V.ii.2.E.1.f · Abnormal progression requires medical support

When hereditary disease had symptoms before service, it may be aggravated if it progresses during service faster than normally expected according to accepted medical authority. This is a factual medical determination based on the record and sound judgment. Apply the appropriate noted-versus-unnoted entrance and aggravation rules when deciding the claim.