Stiffness of unspecified knee, not elsewhere classified

This code signifies a patient's subjective complaint of stiffness in a knee joint where the specific cause or underlying pathology has not been determined or documented. It indicates a functional limitation without an identified etiology.

Use this code when documentation clearly states "stiffness of knee" without further specificity regarding laterality (left or right) or the underlying cause (e.g., osteoarthritis, injury). This code is appropriate when the provider has not yet made a definitive diagnosis for the knee stiffness.

• Avoid using this code if the laterality of the knee is documented (e.g., M25.661 for right knee, M25.662 for left knee).
• Always strive for a more specific diagnosis if available, such as M17.xx for osteoarthritis of the knee.
• This code is often a temporary diagnosis used during initial evaluation before a definitive cause is identified.