If you already have a VA service-connected disability, you may have another condition that was caused by—or made worse by—that disability.

If so, you may be able to file a VA secondary claim.

This is one of the most important concepts to understand if you are trying to build your VA disability claim over time. A secondary condition does not necessarily have to have started during your military service. Instead, you are showing that your existing service-connected disability caused or aggravated another disability.

For example:

• A service-connected knee condition contributes to a hip condition.
• A service-connected back condition causes radiculopathy in the leg.
• Service-connected diabetes contributes to peripheral neuropathy.
• A service-connected condition contributes to sleep apnea.
• A service-connected condition causes or aggravates migraines, GERD, or another diagnosed condition.

Under 38 CFR § 3.310, VA can establish service connection for a disability that is proximately due to or aggravated by a service-connected disease or injury.

The important part is that you need more than simply having two medical conditions.

You need to establish the connection between them.

This guide explains exactly how to file a VA secondary claim, what evidence you should look for, when you may need a medical nexus opinion, and some of the most common mistakes veterans make.

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What Is a VA Secondary Claim?

A secondary claim is a claim for a new disability that is connected to a disability the VA has already service connected.

Think of it like this:

Military service → Service-connected condition → Secondary condition

For example:

Military service → Service-connected knee injury → Hip condition

The hip condition may not have started while you were in the military.

Instead, your argument is that the already service-connected knee condition caused or aggravated the hip condition.

VA describes a secondary service-connected claim as a claim for a new disability linked to an existing service-connected disability.

The “primary” and “secondary” conditions

You will often hear these terms:

Primary condition: Your existing service-connected disability.

Secondary condition: The new disability you are claiming as related to the primary condition.

For example:

Primary condition: Service-connected lumbar spine condition
Secondary condition: Radiculopathy

Or:

Primary condition: Service-connected diabetes
Secondary condition: Peripheral neuropathy

The fact that the VA has already service connected the primary condition can be extremely important because you don’t necessarily have to prove that the secondary condition began during military service.

Instead, you are establishing the relationship between the two conditions.

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What Does 38 CFR § 3.310 Say?

The regulation governing secondary service connection is 38 CFR § 3.310.

It provides two major pathways.

1. The service-connected condition caused the new disability

The first situation is when your service-connected condition actually caused another disability.

For example:

Service-connected diabetes → peripheral neuropathy

If the evidence establishes that the service-connected disability caused the additional disability, secondary service connection may be appropriate.

2. The service-connected condition aggravated the other disability

The second situation involves aggravation.

This means you already have another condition, but your service-connected disability makes that condition worse.

For example:

Service-connected condition → aggravates another diagnosed condition

The regulation recognizes that an increase in severity of a non-service-connected disability caused by a service-connected disability can qualify for secondary service connection, subject to the applicable requirements for establishing the baseline level of severity.

This distinction is extremely important.

You don’t always have to prove:

“My service-connected condition caused this condition from the beginning.”

You may instead be able to establish:

“My service-connected condition made this existing condition worse.”

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How to File a VA Secondary Claim

Here is the process I recommend veterans understand before submitting a secondary claim.

Step 1: Identify Your Existing Service-Connected Disability

Start with the disabilities the VA has already service connected.

Look at your most recent VA rating decision and identify the conditions for which you have an established service connection.

For example, you might already have:

• PTSD
• Knee condition
• Lumbar spine condition
• Tinnitus
• Diabetes
• Sinusitis
• Rhinitis
• Shoulder condition

The next question is:

Could one of these conditions have caused or aggravated another diagnosed condition?

Don’t start by simply looking for a list of conditions that “go together.”

Start with the medical relationship.

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Step 2: Identify the Secondary Condition

Next, determine what additional condition you are claiming.

Ideally, you should have evidence that the condition actually exists.

This might include:

• A diagnosis from your VA doctor
• A diagnosis from a private physician
• Imaging
• Laboratory testing
• Sleep studies
• Specialist evaluations
• Treatment records
• Prescription history
• Other relevant medical evidence

VA states that for a secondary claim, you need evidence showing that you have a new physical or mental condition and evidence showing a link between that condition and the disability that is already service connected. VA says this link will usually require medical records or a medical opinion, although lay evidence can sometimes be accepted.

Don’t overlook the diagnosis

One common mistake is trying to file a claim based only on symptoms.

For example, saying:

“My back hurts and now my leg goes numb.”

is different from having evidence showing a diagnosed neurological condition such as radiculopathy.

Your claim becomes much easier to understand when the condition you’re claiming is clearly identified and supported by medical evidence.

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Step 3: Determine How the Conditions Are Connected

This is the step that can make or break a secondary claim.

Ask:

Did my service-connected disability cause the new condition?

Or:

Did my service-connected disability aggravate the new condition?

You want to identify the actual medical theory connecting the two conditions.

For example:

“My service-connected lumbar spine condition has caused nerve impairment resulting in radiculopathy.”

That’s much more specific than:

“My back condition is related to my leg problems.”

The goal is to explain why the primary condition caused or aggravated the secondary condition.

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Step 4: Gather Your Medical Evidence

Your next step is to collect evidence supporting both conditions and the relationship between them.

Useful evidence may include:

VA medical records

These can document:

• Diagnosis
• Symptoms
• Treatment
• Progression
• Medications
• Provider observations
• Testing
• References to other conditions

Private medical records

Don’t assume VA has access to everything.

If you’ve been treated by a private doctor, obtain the relevant records and submit them with your claim when appropriate.

VA specifically identifies private medical records, doctors’ reports, X-rays, laboratory results, and other medical evidence as potential supporting evidence.

Medical opinions

A medical opinion can be particularly important when the relationship between the two conditions isn’t obvious from the medical records.

For example, a physician might explain why a service-connected condition caused or aggravated another diagnosed condition.

Lay statements

Statements from you, family members, friends, or people who have observed your symptoms may also be useful.

VA recognizes lay evidence as supporting evidence and allows veterans to submit statements describing their condition and related events.

However, remember that a lay statement and a medical nexus opinion serve different purposes.

A veteran can describe what they experienced.

A qualified medical professional may be needed to explain the medical relationship between two conditions.

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Step 5: Consider Whether You Need a Nexus Opinion

This is one of the biggest questions veterans have:

“Do I need a nexus letter for a secondary claim?”

The answer is:

Not necessarily.

There is no rule saying every secondary claim requires a privately obtained nexus letter.

VA may obtain a medical examination or medical opinion when necessary to decide a claim.

However, a medical opinion can be valuable when the connection between the conditions is medically complex, disputed, or not clearly established by the existing medical evidence.

A strong medical opinion should do more than simply say:

“Veteran’s condition is related to service-connected condition.”

It should explain why.

For example:

“It is at least as likely as not that the veteran’s service-connected lumbar spine disability caused the veteran’s diagnosed radiculopathy because…”

The explanation—the medical reasoning—is critical.

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Step 6: Write a Strong Personal Statement

Your own statement can help explain the timeline and your symptoms.

Your statement might explain:

1. When your service-connected condition began affecting you
2. What symptoms you experienced
3. When the additional condition appeared
4. How the symptoms changed over time
5. What treatment you received
6. What your doctors have told you
7. How the primary condition affects the secondary condition

For example:

“After my service-connected knee condition became significantly worse, I began changing the way I walked to avoid putting pressure on my knee. Over time, I developed increasing pain in my hip. My private physician subsequently diagnosed me with a hip condition.”

Your statement establishes the history and observations.

Your medical evidence should help establish the medical relationship.

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Step 7: File the Claim With VA

You can file a disability compensation claim online through VA.gov, or you can submit VA Form 21-526EZ by other available methods.

VA currently identifies VA Form 21-526EZ as the application for disability compensation and related benefits.

When identifying the condition, be as specific as possible.

For example, rather than simply writing:

“Leg problems secondary to back.”

you should identify the diagnosed condition when you can.

For example:

“Right lower extremity radiculopathy secondary to service-connected lumbar spine condition.”

The exact wording will depend on your medical situation.

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Step 8: Submit Your Supporting Evidence

Don’t simply submit the claim and assume VA will figure everything out.

Organize your evidence.

A strong submission might include:

• Your medical records
• Relevant private medical records
• Diagnostic testing
• Medical opinions
• Your personal statement
• Buddy or witness statements when appropriate
• Copies of relevant prior VA decisions
• Other evidence supporting the relationship

VA encourages veterans to submit supporting documents with their claim.

If you have all of your evidence ready when you file, you may also consider whether the Fully Developed Claims process is appropriate for your situation. VA says a fully developed claim involves submitting the application and all evidence you have along with the claim.

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Step 9: Attend Your C&P Exam If VA Schedules One

VA may schedule you for a Compensation & Pension examination.

If you receive an exam appointment, don’t ignore it.

The examiner may evaluate:

• Your diagnosis
• Your symptoms
• The severity of your condition
• Your medical history
• The relationship between your conditions
• Whether additional medical information is necessary

Be accurate.

Don’t exaggerate your symptoms.

But don’t minimize them either.

Explain what actually happens to you on your worst days as well as your typical days, when relevant.

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Step 10: Review the VA Decision

Eventually, VA will issue a decision.

If the secondary claim is granted, the condition will be service connected and assigned an evaluation based on the applicable rating criteria.

If the claim is denied, read the decision carefully.

The most important question is:

Why did VA deny it?

For example, VA might determine that:

• You don’t have a current diagnosis.
• Your primary condition isn’t service connected.
• The evidence doesn’t establish a relationship.
• The medical opinion wasn’t persuasive.
• The evidence showed another cause.
• The evidence did not establish aggravation.
• There wasn’t sufficient evidence to establish the required baseline for an aggravation theory.

A denial doesn’t necessarily mean you can never establish the claim.

It means you need to understand the reason for the denial and determine what review option may be appropriate.

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The 3 Things You Need for a Strong Secondary Claim

When you simplify the process, think about three major pieces:

1. An existing service-connected disability

You need the primary condition to already be service connected.

2. A current disability

You need evidence of the condition you’re claiming.

3. A connection between them

You need evidence establishing that the service-connected condition caused or aggravated the additional disability.

That third piece is where many secondary claims become difficult.

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Example: Back Condition → Radiculopathy

Suppose you have a service-connected lumbar spine condition.

You subsequently develop:

• Shooting leg pain
• Numbness
• Tingling
• Weakness

Your doctor diagnoses you with radiculopathy.

The potential claim becomes:

Service-connected lumbar spine condition → radiculopathy

Now you have:

Primary condition: Service-connected lumbar spine disability

Secondary condition: Diagnosed radiculopathy

Connection: Medical evidence explaining that the lumbar spine disability caused or aggravated the radiculopathy

That’s a much stronger framework than simply saying:

“I have a bad back and my leg hurts.”

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Example: Knee Condition → Hip Condition

Imagine a veteran has a service-connected knee condition.

The veteran begins walking differently because of the knee pain.

Over time, the veteran develops a diagnosed hip condition.

The potential theory is:

Service-connected knee disability → altered mechanics → hip disability

But the fact that the hip condition developed after the knee condition isn’t automatically enough.

You still need evidence supporting the medical relationship.

This is why the medical evidence matters so much.

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Example: Service-Connected Condition → Aggravated Condition

Now imagine that a veteran already had a condition before the service-connected disability became significantly worse.

The veteran’s service-connected condition subsequently makes the other condition worse.

The theory could be:

Existing condition + service-connected disability → increased severity

This is an aggravation theory under 38 CFR § 3.310(b).

The regulation contains specific requirements concerning the baseline level of severity and the extent of aggravation.

This is one reason aggravation claims can require particularly careful medical documentation.

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Common Mistakes With VA Secondary Claims

Mistake #1: Assuming Two Conditions Are Enough

Having two diagnoses doesn’t automatically establish secondary service connection.

You need evidence connecting them.

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Mistake #2: Filing Without a Current Diagnosis

Symptoms are important, but a diagnosis can make the claimed disability much clearer.

Don’t assume that because you experience symptoms, VA will automatically recognize the exact condition you’re claiming.

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Mistake #3: Saying “It’s Because of My Service”

A secondary claim is different from a traditional direct-service-connection claim.

The question is generally not simply:

“Did this happen while I was in the military?”

Instead, you’re trying to establish the relationship between the existing service-connected condition and the new condition.

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Mistake #4: Assuming You Automatically Need a Nexus Letter

A private nexus letter can be useful in some cases, but it isn’t automatically required for every secondary claim.

VA may obtain a medical examination or opinion when necessary.

The more important question is:

What evidence establishes the medical relationship?

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Mistake #5: Ignoring Aggravation

Some veterans believe they have no claim because their service-connected condition didn’t actually “cause” the other condition.

But secondary service connection can also involve aggravation.

Under 38 CFR § 3.310, an increase in severity of a non-service-connected condition caused by a service-connected disability may qualify, subject to the regulation’s requirements.

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Mistake #6: Submitting a One-Sentence Explanation

A statement like:

“I claim sleep apnea secondary to PTSD.”

doesn’t explain much.

Instead, your evidence should tell the story:

What is your primary condition?

What is your secondary condition?

When did the secondary condition develop?

What medical evidence supports the diagnosis?

Why does the medical evidence support a relationship between the two?

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What Evidence Should You Submit?

Here’s a simple way to organize your evidence.

Primary condition

• VA rating decision showing service connection
• Relevant VA medical records
• Private medical records
• Relevant treatment history

Secondary condition

• Current diagnosis
• Diagnostic testing
• Treatment records
• Prescription records when relevant
• Specialist records when relevant

Connection between the conditions

• Medical opinion when appropriate
• Medical records discussing the relationship
• Your personal statement
• Buddy/witness statements when useful
• Medical literature when relevant and properly interpreted

Filing

• VA Form 21-526EZ or online claim
• Supporting evidence
• Personal statement
• Any additional forms VA requires
• C&P examination attendance if scheduled

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Do You Need to Have the Secondary Condition Diagnosed by the VA?

No.

You don’t necessarily need the VA itself to diagnose the condition.

Private medical records can be used as evidence.

VA specifically recognizes private medical records, doctors’ reports, X-rays, laboratory results, and other private treatment evidence as potential evidence for disability claims.

The important issue is whether the evidence establishes the claimed disability and its relationship to the service-connected condition.

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Can You File a Secondary Claim Years After Leaving the Military?

Potentially, yes.

A secondary claim is not necessarily dependent on the secondary condition having appeared during active duty.

The concept is that the condition is linked to an already service-connected disability.

VA specifically describes secondary claims as claims for new disabilities linked to an existing service-connected disability.

However, the effective date and other aspects of your claim can depend on the specific circumstances, so don’t assume that filing later automatically means you will receive benefits back to the date you left the military.

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What If VA Denies Your Secondary Claim?

Don’t simply look at the word “denied.”

Look at the explanation.

Your VA decision should tell you what VA found and why.

For example, suppose VA says:

“The evidence does not establish a nexus between the veteran’s service-connected knee disability and the claimed hip condition.”

That tells you something important.

The problem may not be that VA disputes your knee condition.

The problem may be the connection between the knee and hip conditions.

Understanding the specific reason for the denial can help you determine what evidence or argument may be needed in a subsequent review.

If you’re dealing with a previously denied claim, remember that the appropriate decision-review option can depend on the circumstances of the prior decision and the evidence you now have.

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Frequently Asked Questions

What is a VA secondary claim?

A secondary claim is a claim for a new disability that is caused or aggravated by a disability the VA has already service connected.

Does a secondary condition have to start during military service?

Not necessarily. The key issue is whether the condition is caused or aggravated by an already service-connected disability.

Do I need a nexus letter?

Not automatically. VA may obtain a medical examination or opinion when necessary. A medical opinion can nevertheless be valuable when the medical relationship isn’t adequately established by the existing evidence.

Can I use a private doctor?

Yes. Private medical records and medical opinions can be submitted as evidence in support of your claim.

Can I file for aggravation instead of causation?

Potentially. 38 CFR § 3.310 specifically recognizes aggravation of a non-service-connected disability by a service-connected disability, subject to the regulation’s requirements.

Can I submit buddy statements?

Yes. VA recognizes lay evidence, including statements from people who know about your condition or relevant events.

What form do I use?

VA Form 21-526EZ is the primary application for disability compensation and related benefits, and VA also allows veterans to file online.

What happens after I file?

VA may review your evidence, request additional records, and schedule a Compensation & Pension examination or obtain a medical opinion if necessary.

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The Bottom Line

A VA secondary claim is essentially about proving a chain of events:

You have a service-connected disability.

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You have another diagnosed disability.

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Medical and other evidence supports the connection between them.

That connection can involve causation or, when the requirements are met, aggravation.

The biggest mistake is assuming that simply having two conditions is enough.

Instead, build your claim around the relationship between the conditions.

Before filing, ask yourself three questions:

1. What condition is already service connected?

2. What additional condition am I claiming?

3. What evidence shows that the service-connected condition caused or aggravated it?

If you can clearly answer all three questions, you’re in a much better position to understand what your secondary claim needs.

Want to Find Potential Secondary Conditions?

If you’re trying to figure out what conditions may potentially be secondary to your existing VA disabilities, check out our guide to VA Secondary Conditions List and learn how to identify potential secondary claims and the evidence you may need to support them.

Important: This article is for educational purposes only and is not legal advice. VA disability claims are decided based on the evidence and facts of each individual case. If you need assistance with a claim, consider working with an accredited VA attorney, claims agent, or Veterans Service Organization representative.