Service Connection: The Three Things VA Actually Requires

Most veterans think a VA claim is a medical question. It isn't. It's an evidentiary one.

You can have a diagnosis on paper and a DD-214 in your hand and still get denied, because VA is not asking whether you are sick. VA is asking whether you proved the connection. That is a legal standard, and it has three parts.

Miss one, the claim dies. It is that mechanical.

This post is the long version of what our VA disability claims page summarizes. If VA has already decided your claim, the comprehensive guide to appealing an adverse VA decision covers what comes next.

What are the three requirements for service connection?

Three elements. All of them, every time, unless a presumption is doing the work for you.

Element one and element two are logistics. You request files, you wait, you follow up, you request them again when the first request goes nowhere.

Element three is where claims die.

What is the "nexus" and why does it decide the claim?

The nexus is the etiology: the medical cause and origin of your current condition, tied back to service.

Here is what that means in practice. VA is not going to connect the dots for you. A rater looking at a hearing loss claim sees an audiogram and a service record; nothing in either document says the audiogram is because of the service record. Someone has to say it.

Four kinds of evidence do that work.

Personnel records. These are underused. Your personnel file proves where you were and what you did, which is how you establish hazardous exposure: noise, vibration, solvents, radiation, temperature extremes. A record showing you spent three years on a flight line is nexus evidence for hearing loss and tinnitus. Nobody is going to pull it for you.

Service treatment records. Anything showing the problem was noted or treated at the time. Sick call slips count. A single line in a separation physical counts.

Medical opinions. A licensed provider addressing etiology. The phrase that matters is "at least as likely as not," because that tracks the benefit-of-the-doubt standard VA is supposed to apply. An opinion saying a condition is "possibly related" is worth less than one saying it is at least as likely as not related, with the reasoning spelled out.

Lay statements. Yours, your spouse's, your battle buddy's. These carry more weight than most people expect. A buddy statement can establish an in-service event when the paperwork cannot. Your own statement establishes what you can personally observe: symptoms, when they started, what they stopped you from doing. Write about impact on daily function, not a symptom list. "I stopped driving at night and I sleep about three hours" tells a rater more than "I have insomnia and anxiety."

Will VA automatically order a C&P exam if I don't have a nexus opinion?

No. This is the most dangerous piece of bad advice circulating on the subject.

VA has a duty to assist, but the duty to provide an examination has a trigger. Under 38 U.S.C. § 5103A(d) and 38 C.F.R. § 3.159(c)(4), as read in McLendon v. Nicholson, 20 Vet. App. 79 (2006), VA must provide an exam only when four things are present:

1. Competent evidence of a current disability, or persistent or recurrent symptoms of one;
2. Evidence establishing an in-service event, injury, or disease;
3. An indication that the two may be associated; and
4. Insufficient competent medical evidence already in the file for VA to decide.

The third element is a low threshold on purpose. The Court set it low so VA develops evidence instead of denying on a thin nexus. But low is not zero. File a bare claim with no in-service event and nothing suggesting a link, and VA can deny without ever scheduling an exam.

So do not file naked and wait. Put something in the file that satisfies element three: a treating physician's note, a lay statement describing continuous symptoms, a personnel record showing the exposure. Then the duty to examine fires.

The flip side matters too. When all four elements are met and VA denies without an exam, that is a duty-to-assist error, and it is grounds for a Higher-Level Review return or a Board remand. Know which situation you are in. The VA Appeals Navigator walks the lanes if you are already past a denial.

What are the three types of service connection?

Three routes. Pick the one your facts actually support.

Direct

The condition started in service or was aggravated by it. 38 C.F.R. § 3.303.

One point worth stating plainly, because it gets garbled constantly: direct service connection does not require an unbroken chain of treatment from discharge to today. That is the continuity-of-symptomatology route under § 3.303(b), and it is a separate, narrower path. After Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013), continuity of symptomatology stands alone as a basis for service connection only for the chronic diseases specifically listed at § 3.309(a): arthritis, diabetes, hypertension, psychoses, organic diseases of the nervous system including tinnitus, and others on that list. For those conditions, continuous symptoms can carry the claim without a nexus letter.

For everything else, gaps in treatment do not sink you; a medical nexus opinion does the work instead. Plenty of veterans went twenty years without seeing a doctor because that is what you do. That is not evidence you were healthy.

Secondary

Condition A is already service-connected, and it caused Condition B. 38 C.F.R. § 3.310.

The textbook example is a service-connected knee, an altered gait, and a back condition. Also common: a service-connected condition, a prescribed medication, and GI damage from the medication.

The version people miss is § 3.310(b), aggravation. Your service-connected condition does not have to cause the second condition. If it made a non-service-connected condition worse, you may be compensated for the incremental increase over that condition's established baseline. Sleep apnea aggravated by a service-connected condition is the claim you see most often here.

Secondary claims are the highest-yield thing most veterans are not filing. If you are rated for something, sit down and map what that condition has done to the rest of your body over the last decade.

Presumptive

VA presumes the nexus. You show service in a place during a window, plus a diagnosis on the list, and element three is handled by operation of law.

This is the easiest path when it applies, and it is entirely mechanical. Location, dates, listed condition. If any of the three is off, the presumption does not attach and you are back to direct service connection.

Which presumptions apply, and what are the actual dates?

Dates are the whole ballgame. A location without a date range is useless to you.

Agent Orange, PACT Act expansions. In addition to Vietnam and the Korean DMZ (September 1, 1967 through August 31, 1971), VA now presumes herbicide exposure for:

The Cambodia window is fifteen days. That is not a typo; VA scoped it to the actual spray operation.

Burn pits and post-9/11 toxic exposure. The PACT Act added presumptive conditions tied to Iraq, Afghanistan, and the surrounding airspace after 9/11, along with Gulf War-era Southwest Asia service. Gulf War claims for undiagnosed illness and medically unexplained chronic multisymptom illness are decided under the separate criteria of 38 C.F.R. § 3.317. If your claim was denied before these changes, see our post on why the VA budget says you should refile.

Camp Lejeune. Thirty days of service, consecutive or nonconsecutive, at Camp Lejeune or MCAS New River between August 1, 1953 and December 31, 1987, under 38 C.F.R. § 3.307(a)(7). Eight diseases are presumptive under § 3.309(f):

• Adult leukemia
• Aplastic anemia and other myelodysplastic syndromes
• Bladder cancer
• Kidney cancer
• Liver cancer
• Multiple myeloma
• Non-Hodgkin's lymphoma
• Parkinson's disease

Two things about that list. The disease has to become manifest to a degree of 10 percent or more at some point after service, but there is no deadline by which it had to appear. And VA counts health care eligibility differently than compensation eligibility; a longer list of conditions qualifies for Camp Lejeune health care than for presumptive compensation. Do not read one list and assume it is the other.

If your condition is not on a presumptive list, you are not out. You file it as a direct claim with a nexus opinion. The presumption is a shortcut, not a gate.

Comparing the three pathways

Who can help me file?

Accreditation governs authority to act before VA, not competence. VA accredits attorneys, claims agents, and service-organization representatives; accreditation is what permits someone to represent a claimant in a matter before the agency, ordinarily once the claimant appoints them on VA Form 21-22 or 21-22a. Fees in VA matters are governed by 38 U.S.C. § 5904 and 38 C.F.R. § 14.636, which restrict when and how a representative may charge. Federal rules also allow a person without accreditation to assist with a single claim on an uncompensated basis under 38 C.F.R. § 14.630.

Useful help exists outside that framework. Consultants, coaches, and record-retrieval services do real work, and a veteran who gets his personnel file pulled and his lay statements organized is in a materially better position than one who does not. What accreditation tells you is who may act for you before VA; it does not tell you who is good at their job. Ask what a given service actually does, and get the arrangement in writing.

Three things to do this week

1. Request your complete personnel file, not just your medical records. Most veterans have never seen theirs. That is where exposure evidence lives.
2. Map your secondary claims. List every service-connected condition you have, then list what each one has done to the rest of you.
3. Check your dates against the presumptive tables above. Not the location. The dates. People assume they do not qualify because they served in Thailand instead of Vietnam, and they have been leaving a claim on the table since 1976.

The nexus is the whole game. Everything else is paperwork.

This is general information about how VA adjudicates service connection, not legal advice about your claim, and reading it does not create an attorney-client relationship. Regulations and presumptive lists change; verify current requirements at va.gov before you file.