How to claim the Bilateral Factor (38 CFR § 4.26) — the 10% combined-rating boost VA frequently miscalculates on bilateral injuries
The Bilateral Factor under 38 CFR § 4.26 adds 10% to the combined disability rating for veterans with TWO OR MORE service-connected disabilities affecting paired body parts (both knees, both hands, both feet, both legs, both eyes, both ears, etc.). VA raters MISS this in approximately 25-40% of bilateral cases — leaving veterans at 70% who should be 80%, or 80% who should be 90%. A 10% rating difference can mean $300+/month in additional compensation, $3,600+ per year, $100K+ over a lifetime. CUE (Clear and Unmistakable Error) motion can recover years of back pay if VA failed to apply Bilateral Factor in original rating. 5 steps: identify bilateral disabilities, perform the math correctly, compare to your VA rating, file CUE motion or Supplemental Claim, monitor for retroactive payment.
What you'll need
- VA decision letter showing all SC ratings + combined rating calculation
- VA Combined Ratings Table — 38 CFR § 4.25 — and Bilateral Factor formula — 38 CFR § 4.26
- Online combined rating calculators (e.g., va.gov/disability/about-disability-ratings/) — but verify Bilateral Factor is applied
- VA Form 21-526EZ (for Supplemental Claim) or VA Form 20-0995 (Higher-Level Review) or VA Form 20-0996 (CUE Motion)
- Free CVSO/VFW/Legion/DAV bilingual representative for review and filing
- Calculator OR spreadsheet for bilateral combined rating math
Step-by-step
Step 1: Identify all your bilateral disabilities
BILATERAL DISABILITIES under 38 CFR § 4.26 are SC conditions affecting BOTH SIDES of paired body parts: BOTH knees (left + right knee), BOTH hands, BOTH feet, BOTH legs (above knee — separate from lower legs/feet), BOTH arms, BOTH eyes (separate ratings), BOTH ears (hearing loss + tinnitus may qualify if rated separately), BOTH lungs, BOTH kidneys (rare but possible). EXAMPLE QUALIFIES: SC right knee strain 20% + SC left knee strain 20% = bilateral pair, gets Bilateral Factor. SC right shoulder 20% + SC left shoulder 30% = bilateral pair, gets Bilateral Factor. SC right ankle 10% + SC left foot 20% = NOT bilateral (different body parts). DOES NOT QUALIFY: PTSD + tinnitus (different organs). Sleep apnea + hypertension (single-organ + systemic). Back injury + neck injury (spine is single organ). Right knee + left ankle (different paired sets). REVIEW YOUR VA DECISION LETTER for any conditions affecting paired body parts. Also check secondary conditions — if you developed a SECONDARY condition in the opposite-side body part (e.g., favoring left knee causing right knee pain), file a secondary claim AND ensure Bilateral Factor is applied when granted.
Step 2: Calculate the Bilateral Factor correctly (the formula VA frequently miscalculates)
BILATERAL FACTOR FORMULA per 38 CFR § 4.26: (1) calculate combined rating of bilateral disabilities ALONE using VA Combined Rating Table; (2) ADD 10% of that combined rating to itself; (3) THEN combine that adjusted total with all other non-bilateral SC disabilities. EXAMPLE A: veteran with SC right knee 30% + SC left knee 30% (bilateral pair) + SC tinnitus 10%. WITHOUT bilateral factor (incorrect): combined = 30% + 30% + 10% = 60% per Combined Ratings Table. WITH bilateral factor (correct): bilateral pair combined alone = 51% (30 combined with 30 = 51% per table); add 10% × 51% = 5.1%, round to 5%; bilateral adjusted = 56%; combine with tinnitus 10% = 60% (rounding may produce same result, but in many cases produces higher). EXAMPLE B (where bilateral factor changes the result): SC right hip 20% + SC left hip 20% + SC PTSD 50%. Without bilateral: hip combined = 36%, then with PTSD 50% = 68% → rounded to 70%. With bilateral: hip combined = 36%, +10% × 36% = 3.6%, hip adjusted = 39.6% → 40%. Combined with PTSD 50% = 70%. Same in this example, BUT add a tinnitus 10%: without bilateral = 71% → 70%. With bilateral = 73% → 70%. The rounding rules (38 CFR § 4.25) round to nearest 10% — so Bilateral Factor MOST often matters when it pushes you over a 10% threshold. EXAMPLE C: SC right shoulder 30% + SC left shoulder 30% + SC sleep apnea 50% + SC hypertension 10%. Without bilateral: 30+30=51, +50=76, +10=78 → 80%. With bilateral: 30+30=51, +5.1=56, +50=78, +10=80 → 80%. Same. EXAMPLE D where it changes: SC right knee 20% + SC left knee 20% + SC tinnitus 10% + SC PTSD 30%. Without bilateral: 20+20=36, +10=42, +30=59 → 60%. With bilateral: 20+20=36, +3.6=39.6, +10=46, +30=62 → 60%. WAIT — both same. The 10% boost MOST OFTEN matters when bilateral is high (40%+) and adds new digit. The lesson: ALWAYS calculate both ways; difference often 0-10% depending on rounding.
Step 3: Compare your VA decision letter combined rating to the correctly-calculated rating
PULL YOUR VA DECISION LETTER. Find the section where VA shows the combined rating calculation — typically a numbered list like "Right knee 30%, Left knee 30%, Tinnitus 10%, Combined: 60%." DOES VA SHOW THE BILATERAL FACTOR? Look for language like "Bilateral factor applied," "10% bilateral factor," or "BLF" notation. Many decision letters do NOT explicitly show bilateral calculation — they just state the combined rating. RECALCULATE: use the formula in Step 2 to determine if your combined rating is correct WITH bilateral factor. If the VA combined rating equals your correctly-calculated rating, no action needed. If your correctly-calculated rating is HIGHER than VA's combined rating, you have a Bilateral Factor error — proceed to Step 4. KEY VERIFICATION TOOLS: (a) VA Combined Ratings Table at 38 CFR § 4.25 (Cornell Law: law.cornell.edu/cfr/text/38/4.25); (b) free calculators like va.gov/disability/about-disability-ratings/; BUT VERIFY the calculator includes Bilateral Factor option (some don't); (c) cross-check with CVSO or VSO accredited representative — they see hundreds of cases and can spot Bilateral Factor errors quickly.
Step 4: File the appropriate appeal — CUE motion vs Higher-Level Review vs Supplemental Claim
CHOICE OF LANE depends on when the error occurred and whether new evidence is needed: (A) WITHIN 1 YEAR OF VA DECISION: file Higher-Level Review (VA Form 20-0996) — citing "VA failed to apply Bilateral Factor under 38 CFR § 4.26 to bilateral disabilities [list]." HLR is the fastest route (4-5 month average). NO new evidence needed because rating math is on the existing record. (B) MORE THAN 1 YEAR AFTER DECISION (most common): file CUE Motion (Clear and Unmistakable Error). Use VA Form 21-526EZ marked "CUE motion to correct combined rating per 38 CFR § 4.26 Bilateral Factor." CUE has NO time limit and recovers FULL retroactive back pay (not just 1 year). KEY: CUE requires showing the error was UNDEBATABLE — Bilateral Factor math is mathematical, so this standard is easier to meet than for medical opinion errors. (C) IF FILING NEW CLAIM (e.g., adding a new bilateral pair): use VA Form 21-526EZ for the new claim AND request review of all bilateral pairs in the rating decision via cover letter citing 38 CFR § 4.26. WHAT TO INCLUDE: cover letter or written statement showing your correct calculation step-by-step, citing 38 CFR § 4.26 + 38 CFR § 4.25 + your specific SC disability list with ratings. CVSO/VSO accredited representative will draft this for free. EFFECTIVE DATE for back pay: original effective date of bilateral disabilities (sometimes 5-15 years retro pay).
Step 5: Monitor for retroactive payment + verify all future ratings include bilateral factor
AFTER VA APPROVAL OF BILATERAL FACTOR CORRECTION: VA recalculates combined rating + issues new decision letter showing higher percentage. RETROACTIVE PAYMENT: if filed via CUE, payment is back to ORIGINAL effective date of the bilateral disabilities — could be $10K-$100K+ depending on how many years retroactive. If filed via HLR (within 1-year window), payment is back to the date of the original decision. PAYMENT TIMING: typically lump-sum within 30-60 days of the corrected decision; ongoing increased monthly compensation begins immediately. FUTURE PROTECTION: any future SC rating decisions that ADD a new bilateral disability should automatically apply Bilateral Factor — but VA still misses it ~25% of the time. ALWAYS recalculate after EVERY VA decision letter to catch errors early. SECONDARY APPLICATIONS: if you have non-bilateral SC disabilities and develop a SECONDARY condition in the opposite-side paired body part, the new condition gives you a bilateral pair — file a Supplemental Claim citing the new bilateral pair AND requesting Bilateral Factor application. EXAMPLE: SC right knee + secondary SC left knee due to right-knee favoring → now bilateral, qualifies for bilateral factor on combined rating.
Critical tips
- BILATERAL FACTOR is MOST OFTEN missed by VA when veteran has 3+ disabilities including a bilateral pair. The math gets complex and raters skip the bilateral step.
- CUE Motion (Clear and Unmistakable Error) has NO TIME LIMIT — you can fix Bilateral Factor errors from decisions 10, 20, 30 years ago.
- CUE Motions for Bilateral Factor are EASIER to win than typical CUE because the error is MATHEMATICAL — just plug numbers into the formula. Mathematical errors are "undebatable" by definition.
- RETROACTIVE BACK PAY for CUE goes back to the ORIGINAL effective date of the bilateral disabilities — often $10K-$100K+ for veterans with long-standing claims.
- VA combined rating ROUNDS to the nearest 10% (per 38 CFR § 4.25). Bilateral Factor most often matters when the unrounded total is just BELOW the 10% rounding threshold (e.g., 64% rounds to 60%; with +10% bilateral, becomes 70%).
- SECONDARY conditions in opposite-side paired body parts CREATE bilateral pairs. Track these — file claims to add new bilateral pairs that didn't exist at original rating.
- PAIRED BODY PARTS per 38 CFR § 4.26: knees, hands, feet, legs (above knee), arms, eyes, ears (separate hearing loss + tinnitus may qualify), lungs, kidneys.
- NOT PAIRED: spine (single organ), back+neck, head/face/skull (single), heart, internal organs that don't come in pairs.
- Bilateral Factor + SMC stacking: if bilateral factor pushes you to 70%+ AND you have other criteria, may qualify for Special Monthly Compensation. Always recheck SMC eligibility after bilateral correction.
- CVSO/VFW/Legion/DAV representatives see Bilateral Factor errors WEEKLY. They're used to spotting them — bring your VA decision letter for free review.
- Tinnitus + hearing loss BOTH ears can qualify as bilateral if rated separately for left/right ear. Most veterans rated only "tinnitus" — but bilateral hearing loss with separate left/right ratings = bilateral.
- For PACT Act presumptives or burn-pit related claims with bilateral pairs (e.g., bilateral lung function loss), file the claim AND explicitly request Bilateral Factor in the cover letter.