Navigating the Legal Standard: “At Least As Likely As Not” 

Securing benefits from the Department of Veterans Affairs (VA) can be challenging due to specific legal standards. While the VA aims to support veterans, applicants must provide strong evidence and thorough medical documentation. Understanding this process is essential for veterans seeking the benefits they have earned. 

The entire pursuit of benefits relies on establishing a “service connection” by meeting the evidentiary burden of proof: “At Least As Likely As Not.” This means that a veteran’s disability must be determined to have at least a 50% likelihood of having been incurred in, or caused by, their military service.

Understanding the Standard: More Than Just a Coin Flip 

The “At Least As Likely As Not” standard requires that the evidence supporting the link between service and the current condition is at a minimum equal to the evidence against it. 

The Legal Foundation of “At Least As Likely As Not” 

The true power of this standard is realized through the Benefit of the Doubt Doctrine. The law states: 

“When there is an approximate balance of positive and negative evidence regarding any issue material to the determination of a matter, the Secretary shall give the benefit of the doubt to the claimant.” (38 U.S.C. § 5107(b).) 

This means that if the evidence is an exact 50/50 balance, the VA legally must rule in the Veteran’s favor.  

Distinguishing Medical Probability from Legal Certainty 

It is important to understand that medical professionals establish the probability of a connection, but the VA’s adjudicators apply the legal standard. An Independent Medical Opinion (IMO) or Nexus Letter must explicitly use the requisite legal language, such as “at least as likely as not,” to be considered competent medical evidence with high probative value. A medical opinion that says “it is possible” is generally too weak to overcome negative evidence. 

The Nexus Opinion: The Critical Piece of Medical Evidence 

The Nexus Opinion, or Independent Medical Opinion (IMO), is the most powerful piece of evidence in the Veteran’s control because it directly addresses the link required for service connection. 

Defining the Independent Medical Opinion (IMO) 

A Nexus Opinion is a well-reasoned document prepared by a qualified, independent medical professional that links the current disability to an in-service event, injury, or exposure. This document is crucial when service connection is not presumed or when the VA’s own medical findings are unfavorable. 

Why Expert Rationale is More Important Than a Conclusion 

A simple statement saying a condition may be service-connected holds little weight. A strong Nexus Opinion must: 

• Be Thorough: Show a comprehensive review of all available documentation, including Service Treatment Records (STRs), private medical records, and the Veteran’s sworn statements. 

• Provide a Rationale: Explain the medical and scientific reasoning for the conclusion, citing peer-reviewed literature or established medical principles. 

• Use Compliant Language: Conclude using the mandatory phrases: “at least as likely as not” or “more likely than not”. 

The Evidence Checklist: Laying the Foundation for a Nexus 

A medical professional cannot provide a strong Nexus Opinion without a solid foundation of facts. 

Step 1: Documenting a Current Diagnosis (No Diagnosing) 

The most basic component of a benefits pursuit is a current, formal diagnosis from a treating healthcare provider. Our consulting service focuses on reviewing the Veteran’s existing medical documents to ensure this diagnosis is clearly recorded and may meet VA diagnostic standards. We do not diagnose or treat medical conditions. 

Step 2: Corroborating the In-Service Event or Injury 

The second pillar is providing evidence that a specific event, injury, or exposure occurred during service. While Service Treatment Records (STRs) are the ideal proof, many injuries go undocumented. 

Competent Lay Evidence: Filling the Gaps 

In the absence of official records, Competent Lay Evidence is vital. These are sworn statements from the Veteran (Personal Statements) and/or those who witnessed the event or symptom onset (Buddy Statements). Lay evidence must detail symptoms, their severity, and their persistence from service until the present day, filling the gaps in official records.  

Lay evidence is defined as any evidence not requiring specialized education, training, or experience, provided it conveys matters that can be observed and described by a lay person.

Discover how our medical evidence service is transforming lives 

Clear  medical documentation is crucial for the success of any disability claim.
If you’re unsure about your documentation, talk to one of our licensed medical experts for FREE.   

The C&P Examination: Education, Not Preparation

The Compensation and Pension (C&P) exam is a required medical assessment scheduled and paid for by the VA. 

Purpose and Limitation of the C&P Exam 

The C&P examiner serves as a fact-finder for the VA, not a treating physician for the Veteran. Their objective is to gather information and provide an opinion that may be used to either grant or deny the evaluation. We do not provide C&P “prep” or tell clients what to say.  

At Trajector Medical, we help educate patients on the purpose of the exam and stress the importance of providing an accurate and honest account of their symptoms.

The Value of Your Independent Evidence 

If the VA examiner provides an unfavorable opinion (e.g., “less likely than not”), a high-quality, pre-submitted Nexus Opinion becomes the Veteran’s counter-evidence. The decision-maker must then weigh the opinions of both medical experts, and the well-reasoned, compliant Nexus Letter can serve to balance the record in favor of the Veteran, invoking the Benefit of the Doubt Doctrine. 

The client maintains full control and discretion over what evidence they choose to submit.

Complex Situations & The Medical Evidence Lens 

Our consulting focus extends to the specialized evidence required for common complex evaluation types. 

Secondary Service Connection (The Cause-and-Effect Standard) 

Secondary service connection is pursued when an already service-connected condition is the direct cause of a new condition (e.g., knee arthritis causes an altered gait, potentially leading to a secondary hip injury). The medical evidence in these cases must establish that the service-connected condition is at least as likely as not the proximate cause of the second condition. 

The Difference Between Worsening and Aggravation 

For conditions that existed before service (pre-existing), the medical evidence must prove aggravation. This may require a Nexus Opinion that: 

• Acknowledges the pre-service condition. 

• Demonstrates that service caused a permanent worsening of the condition beyond its natural progression. 

Focusing on Your Evidence Journey 

The evidence you gather is the key to minimizing the time spent in the VA system. The control you have lies entirely within the quality and compliance of the medical evidence you decide to submit.  

Our commitment is to ensure the highest standard of medical evidence consulting to potentially support your pursuit of the benefits you earned.