You can claim more than the injury you left service with. If that injury caused a new problem, or made one worse, the new problem can be its own claim, with its own rating and its own money.

The short version

• A secondary condition is one caused or made worse by a condition VA already service-connected. Service-connected means VA agrees the condition is linked to your service.
• You do not have to prove anything happened in service. You need a current diagnosis and a medical link.
• The key piece of evidence is a written medical opinion that explains the link.
• Secondary ratings can move you to a higher pay level, or help you qualify for TDIU.
• File an Intent to File (VA Form 21-0966) first to protect your effective date.
• If VA denied your secondary claim, you have one year from the decision date to ask for a review.

The claims most veterans miss

Most veterans claim the thing they left service with. The knee. The back. The shoulder. The ringing in the ears.

Far fewer claim what that injury did to the rest of their body over the next twenty years. For example:

• The hip that wore out because of how they had walked since 1998.
• The depression that came from ten years of pain.
• The stomach damage from anti-inflammatory pills a VA doctor prescribed for the first injury.

Each of those can be its own service-connected disability. Each can have its own rating and its own money. This is the most underused tool in the whole claims system. I see it left on the table almost every week.

What secondary service connection really means

A secondary condition is one that was caused by, or made worse by, a disability VA has already service-connected.

The important part is what you do not have to prove. A direct claim needs three things:

1. A current diagnosis.
2. An event in service.
3. A medical link between the two.

A secondary claim needs only two. You need the current diagnosis. And you need a medical link to the condition VA already granted.

Nothing has to have happened in service. Nothing has to show up in your service treatment records. The condition VA connected years ago already covers the "in service" part.

That is why these claims are often easier to win than the first claim was. It is also why it is strange how rarely they get filed.

"Made worse" counts, not just "caused"

Veterans hear "secondary" and think their service-connected condition had to create the new problem from nothing. It does not.

Say you already had a condition, and a service-connected disability made it worse. VA can pay for how much worse it got. This is called aggravation. Here are two examples:

• Diabetes you would have gotten anyway, sped up by weight gain from a mental health medicine.
• Arthritis that was going to show up someday, pushed years ahead because you walk differently.

The claim is not that service caused it. The claim is that a service-connected condition made it worse than it would have been. VA recognizes this kind of claim.

What you can do: Say it clearly when you file. If your claim is about aggravation and you do not use that word, examiners tend to answer only the "did it cause it" question. They find it did not, and they stop there.

The patterns that come up most often

These are the patterns I see again and again. None of them is automatic. Every one of them needs its own medical opinion in your own case.

• Joints making up for other joints. A service-connected knee changes how you walk. Over the years, the other knee, the hip, or the low back pays for it.
• Spine to nerves. A back or neck condition can cause radiculopathy, which is nerve pain or trouble that runs down an arm or a leg. Each arm or leg that is affected can be rated on its own.
• Physical pain to mental health. Depression or anxiety can grow out of long-term pain, lost work, and lost independence.
• Mental health to physical. Sleep apnea, stomach and gut problems, and high blood pressure are all often claimed as secondary to service-connected PTSD or depression.
• Medicine side effects. Years of prescribed anti-inflammatory pills can damage the stomach. Mental health medicine can cause weight gain and other changes in how your body uses energy.
• Scars, amputations, and overuse. Painful scars get their own rating. A lost or damaged arm or leg puts extra load on the other side.

The medical opinion is the claim

Secondary claims almost never fail because the idea was wrong. They fail because nobody put the medical link in writing. This link is often called the "nexus."

A useful opinion comes from a provider who really reviewed your records. It should not come from someone who spent four minutes with you. A good opinion does two things:

• It says the secondary condition is at least as likely as not caused or made worse by the service-connected condition. "At least as likely as not" means there is at least a 50-50 chance.
• It explains why. It shows the exact way the first condition leads to the second.

That last part is what makes an opinion work. A sentence that says "in my opinion these are related" gives the rater nothing to rely on. The rater is the VA employee who decides your claim.

Compare that with two paragraphs that explain the medicine. For example, they might explain how a limp from pain (called an antalgic gait) puts extra load on the hip on the other side (the contralateral hip) over twenty years. That gives the rater something to grant.

A strong opinion also deals with the obvious argument against you. It does not ignore it. If your weight, your age, or your civilian job could be another explanation, the opinion should address it head on.

Why this can raise your rating more than you expect

VA ratings combine. They do not add up. This rule is in 38 CFR 4.25.

Each new rating applies only to the part of you that VA still thinks is healthy. So later ratings raise the total less than simple math suggests. A small rating added to a high one may not change the combined number at all.

That sounds like a reason not to file secondary claims. It is the opposite. The combined number climbs slowly near the top. So the last few conditions are exactly what carry a veteran across a level that pays more.

Under the rates that started December 1, 2025, a veteran at 70 percent with no dependents gets $1,808.45 a month. At 100 percent, it is $3,938.58. That gap is why the third and fourth secondary conditions are worth the trouble.

Secondary ratings also help with TDIU. TDIU means getting paid at the 100% rate because your service-connected conditions keep you from working. Under 38 CFR 4.16, the usual way to qualify needs one of these:

• One disability rated at 60 percent or higher.
• A combined rating of 70 percent, with at least one condition at 40 percent or higher.

A secondary rating is often what supplies that 40 percent condition. Or it pushes the combined rating to 70. TDIU pays at the 100 percent rate, even though the rating itself does not change.

How to file, and how to protect your effective date

You can file a secondary claim at any time. No window closes. There is no penalty for filing years after the first grant.

Step 1: File an Intent to File first

Use VA Form 21-0966. An Intent to File tells VA you plan to file a claim. It:

• Costs nothing.
• Needs no evidence.
• Locks in your effective date. The effective date is the date VA starts paying from, which controls back pay.
• Gives you a full year to get the medical opinion.

If you file online through VA.gov, it starts automatically.

Say it takes you seven months to get a good opinion. That form is the difference between seven months of back pay and none.

Step 2: Name the link on your claim

When you fill out the claim, say how the conditions are connected. Write the new condition as secondary to the specific service-connected disability. Do not make the rater guess what you mean.

If VA already denied a secondary claim

Read the denial for the reason, not just the result. Most denials say something like "no link established." That is a statement about your evidence. It is not a statement about your body.

You have one year from the decision date. Here are your choices:

• Supplemental Claim (VA Form 20-0995): You send new evidence and ask VA to decide again. This is usually the right choice. A proper medical opinion counts as new and relevant evidence, and VA's duty to assist applies. Duty to assist means VA must help you get certain evidence. These have been taking around 59 days on average, against a goal of 125 days.
• Higher-Level Review (VA Form 20-0996): A senior reviewer looks at the same file. You cannot add new evidence. You can ask for an informal conference, which is a phone call with the reviewer.
• Board Appeal (VA Form 10182): A Veterans Law Judge reviews your case. The Board's Direct Review docket has a goal of 365 days. Dockets that allow new evidence or a hearing usually take longer.

Pick the choice that matches what you are missing. If the problem is evidence, adding evidence is the answer.

Rate note: The dollar amounts in this article are VA's rates that started December 1, 2025. VA pay is set to go up 3.6 percent on December 1, 2026, the same as the Social Security cost-of-living increase. Check VA's current rate tables for the newest amounts.

The Jacks Law Group represents veterans nationwide and worldwide from offices in Henderson and Las Vegas, Nevada. David R. Jacks, Jr. is a VA-accredited attorney and a 100% permanently and totally disabled U.S. Army veteran. If you want help with a claim or an appeal, call to schedule a consultation.

Disclaimer: This blog is for general information only. It is not legal advice for your case. Reading it does not, by itself, make us your lawyers. Every VA claim depends on its own facts. Rates, rating rules, and program rules change over time. For advice about your own situation, talk with a VA-accredited attorney.