The Bilateral Factor: The Hidden Bump in Your Rating You Might Be Missing

If you have service-connected conditions affecting both arms, both legs, or both sides of any paired body part, the VA is supposed to give you a small but meaningful boost called the bilateral factor. It's baked into the regulations. It's supposed to be automatic. And yet it's one of the most commonly missing elements in VA rating decisions.

The bilateral factor exists because having disabilities on both sides of your body is functionally worse than having them on just one side. A bad left knee is one thing. A bad left knee and a bad right knee means you can't shift your weight to compensate. The VA recognized this decades ago — but the system doesn't always catch it.

What the Bilateral Factor Actually Does

The bilateral factor adds 10% of the combined value of your bilateral disabilities to your overall calculation. That's not 10 percentage points added to your final rating — it's 10% of the combined bilateral group, which then gets folded into the rest of your VA math. It sounds small, but it can be enough to push you from one compensation tier to the next.

The legal authority is 38 CFR § 4.26. Under that regulation, when a veteran has disabilities affecting paired extremities or paired skeletal muscles, the VA must apply this factor before combining those disabilities with any non-bilateral conditions.

Which Conditions Qualify

The bilateral factor applies when you have service-connected disabilities affecting both members of a paired body part. The most common examples:

• Both legs — knee conditions, ankle instability, shin splints, peripheral neuropathy of both lower extremities, plantar fasciitis in both feet
• Both arms — shoulder conditions, carpal tunnel in both wrists, elbow conditions, peripheral neuropathy of both upper extremities
• Paired skeletal muscles — bilateral muscle injuries affecting corresponding muscle groups on both sides

The conditions don't have to be the same diagnosis. A left knee condition and right ankle condition both affect the lower extremities — that qualifies. Left shoulder impingement and right carpal tunnel both affect the upper extremities — that qualifies too.

The bilateral factor does not apply to conditions affecting paired organs like eyes, ears, or kidneys. Those have their own rating rules. It specifically applies to extremities and skeletal muscles.

Step-by-Step: How the Bilateral Factor Is Calculated

Let's walk through a real example. Say you have four service-connected conditions:

• Left knee degenerative arthritis — 20%
• Right knee instability — 10%
• Left ankle strain — 10%
• PTSD — 50%

Step 1: Identify the bilateral group. The left knee (20%), right knee (10%), and left ankle (10%) all affect the lower extremities. But we need conditions on both sides. The left knee and left ankle are on the same side, and the right knee is on the other. That's bilateral — we have lower extremity conditions on both the left and right sides.

Step 2: Combine the bilateral disabilities using VA math. Start with the highest: 20%. Your remaining "whole person" is 80%. Apply the next 10%: 10% of 80 = 8. Combined so far: 28%. Remaining: 72%. Apply the last 10%: 10% of 72 = 7.2. Combined bilateral value: 35.2%.

Step 3: Apply the bilateral factor. Take 10% of 35.2 = 3.52. Add it back: 35.2 + 3.52 = 38.72. Round to the nearest whole number: 39%. This is your adjusted bilateral group value.

Step 4: Combine the bilateral group with remaining disabilities. Now combine the 39% bilateral group with PTSD at 50%. Start with the highest: 50%. Remaining: 50%. Apply 39%: 39% of 50 = 19.5. Combined: 69.5%. Rounded to the nearest 10 for compensation purposes: 70%.

Now let's see what happens without the bilateral factor. If we just combined all four conditions using standard VA math without the bilateral bump: 50%, 20%, 10%, 10% combines to about 66.5%, which rounds to 70% as well in this example. But change one of those knee ratings to 20% instead of 10%, and the bilateral factor becomes the difference between rounding to 70% versus 80%. The closer you are to a rounding threshold, the more the bilateral factor matters.

The bilateral factor matters most when your combined rating is near a rounding cutoff — sitting at 74% vs. 75%, or 84% vs. 85%. That 2-4 point bump can mean a meaningful increase in monthly compensation. Use the Combined Rating Calculator to see where you land.

Pull up your most recent Rating Decision letter or your VA benefits summary on VA.gov. Here's what to look for:

• Look at your rated conditions. Do you have service-connected disabilities on both sides of the upper or lower extremities? If yes, the bilateral factor should be in play.
• Search for the words "bilateral factor." The rating decision should explicitly mention it and show the calculation. If you have qualifying bilateral conditions and those words don't appear anywhere, something is likely wrong.
• Check the math. Combine your bilateral conditions using VA math, add 10% of that combined value, then combine with your remaining conditions. If the VA's final number is lower than what you get, the bilateral factor may have been omitted.
• Look at the rating codesheet. You can request your full claims file (C-file) which includes the codesheet — the internal document that shows exactly how the VA calculated your combined rating. The bilateral factor should be broken out as a line item.

The most common scenario where the bilateral factor gets missed: a veteran gets rated for one condition, then files a separate claim for a condition on the other side months or years later. The second rater may not connect the two as a bilateral pair, especially if they were rated under different diagnostic codes.

How to Get It Corrected

If you believe the bilateral factor is missing from your rating, you have a few options depending on your situation.

If your rating decision is recent (within one year): File a Supplemental Claim or a Higher-Level Review on VA Form 20-0996. A Higher-Level Review is often the best fit here because you're not submitting new evidence — you're pointing out a calculation error in the existing decision. A senior reviewer will look at the same evidence and check the math.

If your rating decision is older than one year: You may be able to file a CUE (Clear and Unmistakable Error) claim. Omitting the bilateral factor when it clearly should have been applied can meet the CUE standard — the regulation is straightforward, and the failure to apply it is an error of law that's apparent from the record. If a CUE claim is successful, you'd be entitled to back pay from the original effective date of the error.

In either case: Write a clear, specific statement identifying which service-connected conditions are bilateral, cite 38 CFR § 4.26, and show how applying the bilateral factor changes your combined rating. The more you do the math for them, the easier it is for the reviewer to agree with you.

If you're filing a CUE claim, consider working with a VSO or accredited claims agent. CUE claims have a high bar and specific legal requirements — a well-drafted argument makes a significant difference.

Why This Gets Missed So Often

The bilateral factor is supposed to be automatic. The VA's rating software should flag it. But in practice, conditions get rated at different times by different raters. A veteran might get a left knee rating in 2019 and a right ankle rating in 2022, and nobody connects them as a bilateral pair.

Peripheral neuropathy claims are especially prone to this. Many veterans with neuropathy in both lower extremities — common with diabetes secondary to Agent Orange exposure — have bilateral conditions that should trigger the factor. But because each leg gets its own rating line, the bilateral connection sometimes falls through the cracks.

The Bottom Line

The bilateral factor isn't going to double your rating. It's a modest bump — typically a few percentage points. But in a system where your combined rating gets rounded to the nearest 10%, a few points can be the difference between 60% and 70%, or 80% and 90%. That's real money every month, potentially for the rest of your life.

If you have service-connected conditions on both sides — both knees, both shoulders, neuropathy in both legs — pull up your rating decision and look for the bilateral factor. If it's not there, you may be leaving compensation on the table.

Use the Combined Rating Calculator to see how the bilateral factor affects your combined rating, or run the Benefits Finder to see every federal and state benefit you qualify for at your current — or corrected — rating.