VA Bilateral Factor: How Paired-Side Disabilities Boost Your Rating

How having disabilities on both sides of your body can increase your rating

By MilMath Team · Updated June 2026

The bilateral factor is one of the most misunderstood pieces of VA math. It is a small bonus the VA adds to your combined disability rating when you have service-connected conditions affecting both sides of your body — for example, both knees or both shoulders. Because it is applied automatically by the VA and never appears as a separate line on your rating decision, many veterans never realize it was used, or assume it was missed when it actually was not. This article explains how the factor works, when it helps, and how to read your own decision.

What the Bilateral Factor Is

The bilateral factor recognizes that losing function on both sides of the body is more disabling than losing the same function on just one side. If you can favor your good leg, you compensate. If both legs are impaired, you cannot. To account for this, the VA adds an extra 10% on top of the combined value of the paired disabilities before folding that group into your overall rating.

The rule comes from the VA's combined ratings system under 38 CFR § 4.26. It applies to disabilities of:

• Both upper extremities (arms, hands, fingers)
• Both lower extremities (legs, feet, toes)
• Paired skeletal muscles that move those extremities

It does not apply to paired organs or senses such as eyes, ears, or kidneys — those are handled by separate VA rules, not the bilateral factor.

Why VA Ratings Are Not Simply Added

Before the bilateral factor makes sense, you need to know how VA combines ratings at all. The VA never adds percentages straight across. Instead it uses "whole-person" math: each disability is applied only to the portion of you that is still considered healthy.

If you have a 30% disability, the VA treats you as 70% efficient. A second 20% disability is then applied to that remaining 70%, which is 14%, giving a combined value of 44% (rounded to the nearest 10%, that becomes 40%). This is why two 50% ratings combine to 75%, not 100%. The bilateral factor rides on top of this same logic.

How the Factor Is Applied, Step by Step

The order of operations matters, and it is the part people get wrong most often. Here is the sequence the VA follows:

• Step 1: Combine the disabilities that are on paired sides with each other first, using the standard combined-ratings method.
• Step 2: Take 10% of that combined value and add it back in. This is the bilateral factor itself.
• Step 3: Treat the resulting number as a single value and combine it with any remaining, non-bilateral disabilities.
• Step 4: Round the final number to the nearest 10%.

The key insight is that the 10% bonus is added before the bilateral group is combined with everything else. Adding it at the wrong stage produces the wrong answer.

A Worked Example

Example: Suppose a veteran has four service-connected conditions:

• Right knee: 30%
• Left knee: 20%
• Right shoulder: 20%
• Left shoulder: 10%
• Plus a back condition (not bilateral): 20%

The knees are a bilateral pair and the shoulders are a bilateral pair. We handle the extremities together as the bilateral group. Combining all four extremity ratings (30, 20, 20, 10) using whole-person math gives roughly 64%. We then add the 10% bilateral factor: 64% × 0.10 ≈ 6.4%, so 64% + 6.4% ≈ 70.4%, call it 70%.

Now we combine that 70% bilateral group with the non-bilateral 20% back condition. Applying 20% to the remaining 30% gives 6%, so 70% + 6% = 76%, which rounds to 80%. Without the bilateral factor, the same conditions would have combined to about 78%, still rounding to 80% in this case — but in many cases that few extra points is exactly what pushes a veteran from one rounding tier to the next, such as 70% up to 80%.

These figures are illustrative. Your actual decision depends on the exact diagnostic codes and percentages the VA assigns.

When the Bilateral Factor Changes Your Check

Because the final rating is rounded to the nearest 10%, the bilateral factor only changes your monthly compensation when it pushes you across a rounding line. It matters most when:

• Your combined value lands just below a multiple of 10 (for example, at 67%, where the bonus can lift you to 70%).
• You have several bilateral conditions, so the 10% is applied to a larger base.
• The paired conditions are rated 20% or higher on each side.

Even when it does not change the rounded rating, it is still calculated — it simply did not happen to cross a threshold this time.

How to Check Whether the VA Applied It

Your rating decision letter usually shows the math in a combined-ratings table. Look for language noting that a bilateral factor was considered, or a slightly higher combined value than the standard table would produce for your conditions. If you have paired-extremity disabilities and you cannot see any bilateral adjustment, it is worth asking your VA representative or filing for clarification. Errors do happen, especially when ratings are granted at different times.

Frequently Asked Questions

Does the bilateral factor apply to both eyes or both ears?
No. The factor is limited to the extremities and the muscles that move them. Paired senses and organs are covered by other VA rules, not by 38 CFR § 4.26.

Do I have to request the bilateral factor?
No. The VA is required to apply it automatically when you qualify. You do not file a separate claim for it, though you can ask the VA to review your decision if you believe it was overlooked.

Is the bonus exactly 10% added to my final rating?
Not quite. It is 10% of the combined value of the bilateral group, added before that group is combined with your other disabilities — not a flat 10 points tacked onto your final number.

Can one knee and one shoulder count as a bilateral pair?
The factor groups all qualifying extremity disabilities together, so impairments across both arms and both legs are considered as the bilateral group. The pairing concept is about both sides being affected, not about matching the exact same joint.

Estimate Your Own Rating

Our VA Combined Rating Calculator applies the bilateral factor for you when you mark conditions as bilateral, so you can see how it shifts your combined number and whether it crosses a rounding tier.

This article is educational only and is not official VA guidance. For current disability rates and an authoritative decision on your claim, see VA.gov and confirm details with a VA-accredited representative or your finance office.