Monoarthritis, not elsewhere classified, unspecified hip

This code signifies inflammation affecting a single, unspecified hip joint that is not attributable to a specific, classified cause. It indicates a localized inflammatory process within the hip joint without further diagnostic specificity regarding its etiology.

Use this code when documentation clearly states "monoarthritis of the hip" without specifying the laterality (left or right) or the underlying cause (e.g., infectious, crystal-induced, autoimmune). This is appropriate for initial encounters where the specific etiology is still under investigation or when the physician has not documented a more precise diagnosis.

• Avoid using this code if the laterality (left or right hip) is documented; instead, use M13.151 or M13.152.
• Do not use this code if a more specific type of arthritis (e.g., rheumatoid arthritis, gout, septic arthritis) affecting the hip is identified; code the specific condition.
• Query the provider for more specific documentation regarding laterality and etiology if available, to allow for more precise coding.