The VA bilateral factor: the extra 10% on paired-limb disabilities

The bilateral factor (38 CFR 4.26) is an extra 10% VA adds when you have compensable disabilities affecting both arms, both legs, or paired skeletal muscles. VA combines the paired-side ratings, adds 10% of that combined value, and then combines with the rest of your ratings. It's small, easy to miss, and on a borderline case it's the difference between rounding down and rounding up.

Straight talk first

Most veterans have never heard of the bilateral factor, and VA doesn't exactly advertise it. But if you're service-connected on both knees, both legs, both arms — anything paired — you're owed a little extra in the math, and it can tip a 40-something combined value up to the next 10% bracket. That's not nothing; one rounded level can be a meaningfully bigger check. Worth knowing, and worth checking that VA actually applied it.

This is the bilateral-factor deep dive behind how VA combined ratings work.

When it applies

The bilateral factor applies only when there's a compensable disability in each of two paired extremities:

• both lower extremities (e.g., left knee + right knee, or conditions in both legs);
• both upper extremities (e.g., both arms);
• paired skeletal muscles.

It does not apply to a single limb, or to two unpaired conditions (a knee and your hearing don't qualify). This is exactly why knee conditions — which often go bilateral through overcompensation — are a classic bilateral-factor scenario.

How the math works

The order of operations matters (this is straight from 4.26):

1. Combine the ratings for the bilateral disabilities as usual (VA math, not addition).
2. Add 10% of that combined value — add, not combine.
3. Treat that as a single value.
4. Then combine with your remaining ratings, in order of severity.

Because the 10% is added before the final combinations, it can nudge your combined value over a rounding threshold — and your rounded rating only changes pay at each 10% step.

Don't do it by hand — and verify VA's math

The VA Combined Rating Calculator applies the bilateral factor for you, so you can see the real effect. VA is supposed to apply it automatically when paired-extremity disabilities are service-connected — but errors happen, so check your decision math. If it was missed, that's the kind of thing a Higher-Level Review is built to fix.

Pointman is education-only and not VA-accredited; we make sure you understand the math so nothing gets left on the table.

Key takeaways

• The bilateral factor (4.26) adds 10% for compensable disabilities in both arms, both legs, or paired muscles.
• Order: combine the paired ratings → add 10% → then combine with the rest.
• It applies only to paired extremities — not a single limb or unpaired conditions.
• On a borderline rating it can round you up a level; verify VA actually applied it.

Sources

• 38 CFR 4.26 — bilateral factor: https://www.law.cornell.edu/cfr/text/38/4.26
• 38 CFR 4.25 — combined ratings table: https://www.law.cornell.edu/cfr/text/38/4.25
• VA — Disability ratings: https://www.va.gov/disability/about-disability-ratings/