Musculoskeletal System§ 4.71aUpdated
Rating criteria

VA Diagnostic Code 5256Knee, ankylosis of:

Rated from 30% to 60% under § 4.71a. Here is what the VA requires at each level.

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What each rating requires

The VA assigns the highest level your evidence actually supports. Read up the stack until your records stop matching.

  1. 60%

    Extremely unfavorable, in flexion at an angle of 45° or more

  2. 50%

    In flexion between 20° and 45°

  3. 40%

    In flexion between 10° and 20°

  4. 30%

    Favorable angle in full extension, or in slight flexion between 0° and 10°

Knee Ankylosis — VA Disability Rating (Diagnostic Code 5256)

Body System: Musculoskeletal System Regulation: 38 CFR § 4.71a, Diagnostic Code 5256

What Is Knee Ankylosis?

Ankylosis of the knee refers to a knee joint that has become stiff or fixed, leaving it locked in a particular position. Because the joint no longer moves freely, the angle at which the knee is fixed plays a central role in how the condition is evaluated.

Under the VA's rating schedule, knee ankylosis is rated under Diagnostic Code 5256, which is part of the musculoskeletal criteria found in 38 CFR § 4.71a.

Available Rating Levels

The VA assigns a disability rating for knee ankylosis based on the position and angle at which the knee is fixed. The available rating levels are:

RatingCriteria
60%Extremely unfavorable, in flexion at an angle of 45° or more
50%In flexion between 20° and 45°
40%In flexion between 10° and 20°
30%Favorable angle in full extension, or in slight flexion between 0° and 10°

What the VA Looks For

When evaluating knee ankylosis under Diagnostic Code 5256, the VA focuses on the angle at which the knee is fixed:

  • Full extension or slight flexion (0° to 10°) is considered a more favorable position and corresponds to the 30% level.
  • Greater degrees of flexion — where the knee is fixed in a more bent position — correspond to progressively higher ratings, moving through the 40% (10°–20°) and 50% (20°–45°) levels.
  • The most severe positions, described as extremely unfavorable with the knee fixed in flexion at 45° or more, correspond to the 60% level.

The specific angle of the fixed joint is the key factor that determines which rating level applies.

These criteria are a rendering of § 4.71a, diagnostic code 5256. The official version is the one that governs your rating.

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What next

How to claim this

Knowing the criteria is the first half. Getting your file to show them is the second.

  1. Find your level in the stack

    Read each rung against what your medical records already say. The level your records document today is the one the VA can support today.

  2. Name the gap

    Look at the rung above yours and write down exactly what it asks for that your file does not show yet — a diagnosis, a measurement, a prescribed brace, a doctor’s opinion linking it to service.

  3. Claim it by code

    File under diagnostic code 5256 and attach the evidence for the level you are asking for. Other Musculoskeletal System codes may cover your secondary conditions.

Find out which rating your evidence supports.

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