Knee ratings come from one place: the General Rating Formula for diseases and injuries of the knee in 38 CFR 4.71a. Unlike many conditions, the schedule does not rate knee pain directly. It measures four things - how far the knee bends, how far it straightens, whether it is stable, and whether it has fused - and assigns a percentage to each finding. This guide assumes the knee is already service connected.
Understanding those criteria before the C&P exam matters, because the measurements taken that day become the rating. Our VA disability rating calculator shows how a knee rating combines with your others.
Limited flexion - Diagnostic Code 5260
Normal knee flexion is roughly 135 degrees - the heel approaching the buttock. Flexion is measured with a goniometer, and the schedule assigns:
- Flexion limited to 60 degrees - 0 percent (noncompensable)
- Flexion limited to 45 degrees - 10 percent
- Flexion limited to 30 degrees - 20 percent
- Flexion limited to 15 degrees - 30 percent
Limited extension - Diagnostic Code 5261
A knee that cannot fully straighten is measured the same way. Extension lag - the inability to reach a fully straight leg - is rated:
- Extension limited to 5 degrees - 0 percent (noncompensable)
- Extension limited to 10 degrees - 10 percent
- Extension limited to 15 degrees - 20 percent
- Extension limited to 20 degrees - 30 percent
- Extension limited to 30 degrees - 40 percent
- Extension limited to 45 degrees - 50 percent
Both criteria can apply
Flexion and extension are separate measurements of the same joint, and the schedule rates them separately when both are limited. A knee that bends only to 40 degrees and cannot straighten past 12 degrees receives the 10 percent flexion evaluation and the 10 percent extension evaluation, which are then combined with everything else under 38 CFR 4.25.
Instability - Diagnostic Code 5257
A knee that gives way, locks, or subluxes is evaluated separately at 10, 20, or 30 percent under Diagnostic Code 5257, based on the frequency and severity of instability episodes. Because instability is a different manifestation of disability from limited motion, it is generally rated in addition to the flexion and extension criteria - this is not pyramiding under 38 CFR 4.14.
Our knee instability guide covers what examiners look for and how episodes are documented.
Where veterans start
Every case is different, and there is no obligation at any step. When veterans want to understand what their records actually support, these are the two most common starting points:
- Medical records review
A licensed physician reviews your records for a $250 flat fee and identifies which knee conditions the available evidence may support. The fee is refunded in full if nothing supportable is identified.
- Nexus letter
When the records support one, a licensed provider writes the medical opinion that addresses the link between your knee condition and your service or an already service-connected disability.
Ankylosis - Diagnostic Code 5256
When the knee has fused, the schedule rates the position of the fusion: 20 percent for a favorable angle and 30 percent for an unfavorable angle, such as fusion in flexion or in less than useful extension. Ankylosis replaces the motion criteria because there is no motion left to measure.
Painful motion - the 10 percent minimum
38 CFR 4.59 provides that when motion is painful, the minimum evaluation is 10 percent even where the range itself is noncompensable. This is the single most underused criterion in knee claims: a veteran with full-ish range but pain on movement may still be entitled to a compensable evaluation, provided the record documents the pain and the functional loss that accompanies it.
Painful motion and loss of function explains what the examiner must document for this rule to work.
Arthritis and knee replacement
Degenerative arthritis of the knee is diagnosed under Diagnostic Code 5003, but the rating still follows motion - imaging establishes the diagnosis, and the flexion, extension, and painful motion criteria set the number. After a total knee replacement, Diagnostic Code 5055 provides a 100 percent evaluation for one year, followed by re-evaluation on residuals with a minimum 30 percent.
Putting the numbers together
Every knee evaluation - each knee, each criterion - enters the combined ratings table in 38 CFR 4.25. For example, a knee rated 30 percent combined with a back rated 20 percent produces a combined 40 percent, not 50, because the table applies each subsequent rating to the remainder.
The practical takeaway: small findings add up, and the difference between 0 and 10 percent on a single criterion often decides whether an entire condition is compensable.
Frequently asked questions
What percentage is limited flexion of the knee?
Under Diagnostic Code 5260 in 38 CFR 4.71a, flexion limited to 60 degrees is rated 0 percent, 45 degrees is 10 percent, 30 degrees is 20 percent, and 15 degrees is 30 percent. Painful motion in any range carries a separate 10 percent minimum under 38 CFR 4.59.
Can the VA rate limited flexion and limited extension separately?
Yes. Flexion and extension are separate criteria under 38 CFR 4.71a, and both may be assigned when both are limited. The evaluations are combined with each other and with all other ratings under 38 CFR 4.25.
Can I get instability rated on top of a motion limitation?
Generally yes. Recurrent subluxation or lateral instability is evaluated separately under Diagnostic Code 5257, at 10, 20, or 30 percent, because giving way is a different manifestation from limited motion. The VA may not, however, compensate the same manifestation twice under 38 CFR 4.14.
What rating does a total knee replacement get?
Under Diagnostic Code 5055, a knee replacement is rated 100 percent for one year following the implantation, then re-evaluated on residuals with a minimum 30 percent evaluation under the arthritis criteria in Diagnostic Code 5003.